In its cross-examination on Thursday of Casandra Ventura, the singer known as Cassie, Sean Combs’s defense team is trying to persuade jurors she was a willing participant in the marathon sex sessions with prostitutes he called “freak-offs.” Among the messages shown, many of them sexually explicit, was one Ms. Ventura sent to Mr. Combs in 2009: “I’m always ready to freak off.”

The defense had acknowledged in its opening statement on Monday that Mr. Combs was responsible for domestic violence and had an unconventional sex life. But jurors were told then that the evidence would show he was not guilty of the charges of sex trafficking and racketeering conspiracy.

Abusive relationship: Ms. Ventura testified that Mr. Combs raped her, blackmailed her with explicit videos of what he called freak-offs — drug-fueled sex sessions with prostitutes — and was routinely violent to her, causing bruises and gashes. After Mr. Combs discovered she had begun dating the rapper Kid Cudi, she said, he told her he was going to hurt both of them.

Hotel assault: In her testimony, Ms. Ventura revealed what happened before and after the surveillance video that showed Mr. Combs striking and dragging her in a hotel hallway. She had fled their room when Mr. Combs gave her a black eye during a freak-off, she testified. And hours after he chased her down the hallway in a towel, she said, he was banging and yelling outside her apartment.

No video or photography: In keeping with longstanding rules at federal courts, there will be no video or photography from the courtroom. The New York Times has a team of reporters at the courthouse, including one in the courtroom. Read our coverage from Day 1, Day 2 and Day 3 of the trial.

Before the defense could enter into evidence a set of communications between Casandra Ventura and Sean Combs, Ventura reviewed them thoroughly on paper first from the witness stand. They were emails, text messages and photos from their relationship.

The defense has characterized Combs’s sexual preferences as part of a “swingers” lifestyle — in contrast to the government’s allegations of sex trafficking and coercion. Combs’s lawyer asked Ventura about that “swingers” lifestyle, and Ventura testified that multiple times she watched Combs have sex with another woman, a reversal of the typical voyeuristic arrangement that played out during their relationship.

The cross-examination is swinging between the freak-offs at the center of the case and other topics. Ventura is currently reading more sexually explicit messages between her and Combs, this time from 2012. The defense seems to be highlighting how, in this conversation, Combs asked about Ventura’s desires and preferences.

There was a very brief but charged back-and-forth between Casandra Ventura and Sean Combs’s lawyer about the effect of the lawsuit she filed in 2023 that he quickly settled for $20 million.

“When your lawsuit was publicized in November 2023, you understood that his career was ruined at that point, right?” his lawyer, Anna Estevao, asked.

“I could understand that, yeah,” Ventura replied.

Ventura was smiling as one of Combs’s defense lawyers read a long email she sent to him shortly after their relationship began. (Ventura suggested that the lawyer read that one aloud, saying, “It’s making me giggle because it’s from 2007.”)

“It was usually, like, a one-way street when it came to messages like this,” she testified.

Early in today’s cross-examination of Casandra Ventura, a lawyer for Sean Combs asked her to recall the love and passion that existed in the early stages of her relationship with the mogul, and cited many flirtatious messages between them. “I miss you sooo much and I’d fly wherever you needed me whenever!!!!!!!” Ventura wrote to him in 2008. In other messages, Ventura expressed eagerness for freak-offs, the marathon sex sessions at the heart of the case.

The testimony markedly differed in tone from Ventura’s questioning by prosecutors over the last two days, in which she described their freak-offs as nightmarish horrors in which she was forced to participate in degrading, drug-fueled sex for sometimes days at a time.

The questioning today was aimed at proving one of the defense’s key arguments: that Ventura, and other women involved in the case, were not coerced into sex, but rather were willing participants.

Casandra Ventura had been monotone and seemed a bit resigned while reading her sexually explicit messages to Sean Combs. She became a bit more animated while discussing her rise to fame in music, describing her 21st birthday party in Las Vegas — which Britney Spears attended, thanks to an invitation from Combs — and a “bad” early TV performance on BET, which Combs helped her move on from.

Much of the cross-examination of Casandra Ventura so far has revolved around the issue of consent in freak-offs.

It was clear from Ventura’s communications with Sean Combs that she had conflicting feelings about these sexual encounters. She testified on Wednesday that she plainly did not want to participate in them because they made her feel “disgusting” and “empty.”

But with the messages the defense has presented today, Combs’s lawyer has been trying to make the argument that Ventura’s hesitancy was more about her fear of being relegated to the role of freak-off partner rather than Combs’s true girlfriend.

It was only about a half-hour into the cross-examination of Casandra Ventura that a lawyer for Sean Combs drew on messages the couple exchanged, in an attempt to establish one of the defense’s key arguments in the case: that Ms. Ventura, and other women involved in the case, were willing participants in the sex marathons known as “freak-offs.”

Anna Estevao, the defense lawyer questioning Ms. Ventura on Thursday, presented a message the singer wrote to Mr. Combs in 2009, that read, “I’m always ready to freak off lolol.”

In another exchange from around that time, Ms. Ventura expressed her excitement in graphic terms, and he told her: “I can’t wait to watch you. I want you to get real hott.”

She answered: “Me too. I just want it to be uncontrollable.”

Conversations like those, which could involve both explicit flirtation and logistical planning about their meetings and preparations, were “somewhat typical” for the two, Ms. Ventura testified.

Those messages showed a very different side of the relationship than what Ms. Ventura described in the first two days of her testimony, under questioning by prosecutors. Over hours of sometimes excruciating testimony, she said that Mr. Combs had forced her to take part in “hundreds” of these episodes over about 10 years, and used violence and threats of releasing explicit videos from the freak-offs as what she called “blackmail material.”

Mr. Combs, who is charged with sex trafficking and racketeering conspiracy, has pleaded not guilty, and his lawyers have vehemently denied that any of his sexual encounters were not consensual.

In the first hours of her cross-examination on Thursday, Ms. Estevao also recalled parts of Ms. Ventura’s testimony from earlier in the week, when the singer said she had agreed to take part in freak-offs because she loved Mr. Combs and wanted to make him happy.

Ms. Estevao, whose tone was measured, calm and conversational, began her questioning by asking about tender and flirtatious messages Ms. Ventura and Mr. Combs had written each other in the early stages of their relationship.

“I miss you sooo much and I’d fly wherever you needed me whenever!!!!!!!” Ms. Ventura wrote in 2008.

Ms. Estevao asked her: “You knew the Sean that he didn’t want anybody else to see but you.” Ms. Ventura did not disagree with her.

But Ms. Ventura showed some resistance when Ms. Estevao’s questioned her motivation for participating in the sex marathons. In one exchange, the lawyer asked, “So, to make him happy you told him that you wanted to do freak-offs, right?”

“No,” Ms. Ventura replied. “There’s a lot more to that.”

Whether Ms. Ventura, and other woman involved in the case, participated in the freak-offs willingly is a crucial point of dispute in the trial.

During the defense’s opening statement on Monday, Teny Geragos, one of Mr. Combs’s lawyers, described the women at the center of the government’s case as “capable” and “strong.”

“For Cassie, she made a choice every single day for years. A choice to stay with him — a choice to fight for him,” she said. “Because for 11 years, that was the better choice. That was her preferred choice.”

The defense is focusing on a message that Ventura sent to Combs in 2009 that expresses some conflicting feelings about freak-offs.

She wrote, in part: “When we used to freak off when we were so in love. There were no questions asked, it felt right, like it literally made sense for the next step in our sex life together. I get nervous that i’m just becoming the girlfriend that you get your fantasies off with and that’s it. I don’t get the other part… Anymore at least.”

Combs’s defense lawyer, Anna Estevao, asked Ventura if her hesitation reflected in the message came from a concern that she wouldn’t be seen as his “full girlfriend” because of her participation in these sexual encounters with male escorts.

“I think that’s a way to look at it I guess, yeah,” Ventura replied.

The messages between Ventura and Combs in 2009 involve discussion of some logistics before the freak-offs (buying candles at a pharmacy) and their aftermath. In one message, Ventura asked Combs if he had any more pills — she said she was taking opiates at the time — and in another, she told him, “I just deleted our little vid” off her camera, calling it “dope.”

The defense has picked up again with the sexually explicit messages that Casandra Ventura sent to Sean Combs in anticipation of a freak-off in 2009.

“I can’t wait,” Combs wrote.

“I can’t wait either,” she replied.

Casandra Ventura is back in the witness box. She is clutching what appears to be a chain of beads with a tassel, and is watching the jurors as they file in.

Sitting between his lawyers, Sean Combs, who is wearing a sand-colored sweater and a collared shirt, has been more fidgety today than he was the last two days. He has been leaning back and forth, and taking his black-framed glasses on and off. During the break, Combs handed a note to his lawyer who was leading the cross-examination of Ventura. Combs’s three sons and mother, Janice Combs, are in the spectators’ gallery.

Ventura whispered to the judge, and he then called for a 10-minute break. We had just been looking at a sexually explicit message Ventura had sent to Combs years ago.

The defense’s goal is to establish that there was nothing coercive about freak-offs between Sean Combs and Casandra Ventura. The jury was seeing messages from 2009 in which Combs and Ventura were discussing a potential freak-off with an escort named Jules who is coming up again and again at trial.

“I’m always ready to freak off lolol,” Ventura wrote.

Ventura has testified that she never wanted to participate in freak-offs but did so to please Combs.

The defense spent about a half-hour establishing the love and passion in the relationship between Combs and Ventura. Now, we’re starting to get into the voyeuristic sexual encounters known as freak-offs at the center of the case.

“So, to make him happy you told him that you wanted to do freak-offs, right?” said Anna Estevao, the lawyer cross-examining Ventura.

“No,” she replied. “There’s a lot more to that.”

Anna Estevao, Sean Combs’s lawyer, asked Casandra Ventura why she fell in love with him. Ventura described the beginning of their relationship — when she was 19 and he was in his mid-30s — as fast-paced and “scary.” But she testified that “his real personality — or at least what I thought was his real personality — came out and I liked who he was.” She called Combs “sweet” and “attentive.”

The first pieces of evidence from the defense were loving messages between Casandra Ventura and Sean Combs from the beginning of their relationship.

“I miss you sooo much and I’d fly wherever you needed me whenever!!!!!!!” Ventura wrote in 2008.

As is typical in cross-examinations, there are plenty of objections from the other side, making the testimony slower and more stilted.

Ventura had her opportunity to tell a sweeping narrative about her life and relationship with Combs, and now it’s time for the defense to try to get as much useful evidence for his side in front of the jury.

“You knew the Sean that he didn’t want anybody else to see but you,” Anna Estevao, a lawyer for Sean Combs, says. The defense has begun trying to establish that Casandra Ventura’s relationship with Combs was long-term and loving, but jealousy-fueled and troubled. Ventura did not disagree with her.

Anna Estevao, a lawyer for Combs, opened her cross-examination of Ventura with this question: “You and Sean Combs were in love for 11 years, right?”

“Yeah,” she said.

Ventura has entered the courtroom and is in the witness box. She is wearing a double-breasted black suit jacket over a light colored shirt. Yesterday, after hours of direct testimony recounting her abusive relationship with Combs, the music mogul turned to his family and mouthed the words, “I’m OK.” Now, she will be questioned by his lawyers.

Across two days on the witness stand, Casandra Ventura, a longtime girlfriend of Sean Combs, delivered hours of testimony about a relationship filled with harrowing physical abuse and meticulous control, and defined by the expectation that she would fulfill his sexual fantasies.

Ms. Ventura, the government’s star witness, will now face questions from Mr. Combs’s lawyers. Some might even come directly from Mr. Combs, who has been passing notes to his legal team throughout the proceedings.

The defense has acknowledged responsibility for domestic violence — including against Ms. Ventura — but has vehemently denied that his behavior warrants the charges against him of sex trafficking and racketeering conspiracy.

The lawyer expected to question Ms. Ventura is Anna Estevao, who has rarely been the lead voice for the team during court proceedings to this point. She faces the delicate task of challenging the testimony of a visibly pregnant woman who testified that years of physical violence and sexual coercion by Mr. Combs led her to such emotional distress that she considered suicide.

Here are a few things we can expect from the cross-examination.

Mr. Combs is charged with sex-trafficking Ms. Ventura. To prove that, the government has to convince the jury that Mr. Combs forced or coerced her into sex parties with male prostitutes known as “freak-offs.”

Ms. Ventura testified that during her relationship with Mr. Combs, she repeatedly followed his directions and felt powerless to do otherwise. But the defense is likely to try highlighting moments when she might have displayed agency.

Teny Geragos, one of Mr. Combs’s lawyers, previewed this strategy during the defense’s opening statement when she described the women at the center of the government’s case as “capable” and “strong.”

“For Cassie, she made a choice every single day for years. A choice to stay with him — a choice to fight for him,” she said. “Because for 11 years, that was the better choice. That was her preferred choice.”

The government has tried to highlight moments when Mr. Combs was violent in the context of a freak-off — most notably, during his assault of Ms. Ventura at a Los Angeles hotel in 2016.

But the defense has argued that Mr. Combs’s violence has typically been fueled by romantic jealousy or drug use, not the freak-offs themselves. In criminal law, Ms. Geragos said in her opening statement, that equates to a charge of assault, not sex trafficking.

“As you look at the evidence and as you evaluate Cassie and Combs’s relationship,” she said, “you will see that their fights, their cheating, their jealousy, it typically surrounded his cheating or it surrounded hers.”

Ms. Ventura testified that Mr. Combs turned video of the freak-offs into “blackmail materials,” saving the footage despite her requests that he delete it and threatening to release videos when he was angry with her. This accusation is at the heart of the government’s case that these sexual encounters were coerced.

The defense has been trying to undercut that claim by highlighting to the jury that the videos of freak-offs that are evidence in the case did not come from Mr. Combs’s devices. They came from Ms. Ventura’s.

When the government raided Mr. Combs’s homes last year, Ms. Geragos said in her opening statement, they seized “countless” electronic devices. But, she said, “the only freak-off videos you will see or hear about at this trial came from her devices that she kept for five years.” (Ms. Ventura testified that the devices had long been broken.)

It is possible during cross-examination that jurors will see clips from those videos. Because the footage is sexually explicit and involves women who have made allegations of sexual abuse, the evidence will be sealed, meaning it will not be shown to the entire courtroom.

Sean Combs’s family rallied around him after his arrest in September on charges of racketeering conspiracy, sex trafficking and transportation to engage in prostitution. His children said then that they would “hold on to the truth, knowing it will prevail and nothing will break the strength of our family.”

Their support has continued this week during the federal trial in Lower Manhattan for Mr. Combs, who has pleaded not guilty.

On Monday, the court gallery included an extended group of Mr. Combs’s family members, including six of his seven children: Quincy Brown, Justin Combs, Christian Combs, Chance Combs and the twins D’Lila and Jessie Combs. (His youngest child, 2-year-old Love Sean Combs, was not in attendance.)

And in the second row sat Janice Combs, his mother.

When her son was tried in a New York State Court in 2001 on gun possession and bribery charges after a nightclub shooting, Mrs. Combs was there every day, often bringing him a brown-bag sandwich lunch. (Mr. Combs was acquitted.)

The statement that Mr. Combs’s children put out on social media after he was arrested last year read: “The past month has devastated our family. Many have judged both him and us based on accusations, conspiracy theories, and false narratives that have spiraled into absurdity on social media. We stand united, supporting you every step of the way. We hold onto the truth, knowing it will prevail, and nothing will break the strength of our family. WE MISS YOU & LOVE YOU DAD.”

They have not publicly commented on the case since the trial began.

On the first day of testimony, Mr. Combs’s daughters left the courtroom during especially explicit testimonies about sex. His sons remained in the courtroom and occasionally passed notes to one another.

Before Casandra Ventura, Mr. Combs’s former girlfriend, testified on the second day of the trial, his children and other family members gathered outside the courtroom and bowed their heads to pray.

Mr. Combs’s mother and three sons were once again in the gallery on Wednesday and Thursday morning. His three teenage daughters were nowhere to be seen.

After Casandra Ventura’s testimony ended a little after 4 p.m. on Wednesday, Sean Combs’s lawyers told the judge they wanted to delay her cross-examination until Thursday so they could have the balance of the afternoon to speak with their client before he was returned to custody at 6.

“This is a very important cross,” said Marc Agnifilo, one of Combs’s lawyers, during a sidebar discussion between the judge and lawyers from both sides, which was not heard by the jury.

But the prosecution wanted the defense’s questioning to begin immediately. “This witness is very, very pregnant,” said Maurene Comey, one of the prosecutors, according to the court transcript. “We are afraid she could have the baby over the weekend.” Then Ventura asked for a break, and the judge, Arun Subramanian, said “that may have solved the issue.”

Ventura’s cross-examination, as well as any “redirect,” or follow-up questions from both sides, are expected to last through Friday.

Each morning of the trial, Sean Combs is transported to the Manhattan courtroom from the Metropolitan Detention Center, a federal jail on the Brooklyn waterfront where he has been held since shortly after his arrest in September.

Mr. Combs — or inmate 37452-054 — has been living in an area of the jail known as 4 North, a fourth-floor dormitory-style unit where roughly 20 men are housed. The unit is known for holding high-profile inmates and government informants. Up until recently, one of Mr. Combs’s fellow inmates in the unit was Sam Bankman-Fried, the cryptocurrency mogul who was convicted of fraud.

Life in the jail involves several compulsory check-ins at one’s bunk each day and a rotating food menu: The second Friday of the month, for example, means lasagna or “pasta fazool” for the vegetarians. Inmates are allowed to spend up to $180 every two weeks at the commissary, using money that family and friends can funnel into their accounts. Packets of mackerel, known as “macks,” operate as a kind of currency between inmates; they’re $1 each.

The music mogul’s lawyers fought for Mr. Combs to be released on bail, but three judges ruled that he posed too much of a threat to the community — and of witness tampering — to be released ahead of his trial.

During hearings ahead of his trial, Mr. Combs typically wore tan jail clothes to court. For the trial, the judge approved access to five button-down shirts, five pairs of pants, five sweaters and two pairs of lace-less shoes.

In her final moments of direct testimony at the federal trial of Sean Combs on Wednesday, Casandra Ventura revealed the amount of a civil settlement that Mr. Combs and his businesses paid her after she filed a bombshell lawsuit in November 2023.

Mr. Combs’s lawyers had previously disclosed that the payment was a “substantial eight-figure settlement.” Ms. Ventura clarified in court that she had received $20 million.

The lawsuit, which accused Mr. Combs of years of physical abuse and sexual coercion, was settled one day after it was filed. But it precipitated a deluge of lawsuits and the federal criminal investigation that resulted in the music mogul’s arrest on racketeering conspiracy and sex-trafficking charges.

Mr. Combs has vehemently denied that he coerced Ms. Ventura — or anyone — into sex and has pleaded not guilty to all of the charges against him.

On the witness stand in Federal District Court in Lower Manhattan, Ms. Ventura testified for hours on Wednesday about injuries she said she received from physical abuse by Mr. Combs, and detailed the drug-dazed sex marathons with male escorts that she said occurred “hundreds” of times throughout their decade-long relationship.

The defense first disclosed months ago that before Ms. Ventura filed her lawsuit, a lawyer representing her approached counsel for Mr. Combs and offered to sell the rights to a book she had written that detailed her account of their relationship. The suggested price: $30 million.

On the stand, Ms. Ventura confirmed that proposal.

“I wanted to be compensated for the time, the pain,” Ms. Ventura testified, as well as for the “many, many years” trying to “fix” her life.

Ms. Ventura said she wrote the book during and after she went to rehab in 2023, which she described as involving “trauma therapy” and coming off Valium. She said her mother helped her get the materials organized. She decided to send chapters to Mr. Combs.

“I really wanted Sean to read the information,” Ms. Ventura testified. “I wanted him to understand what I had to learn to understand over that period.”

Ms. Ventura said she checked with one of his top employees, Kristina Khorram, to check if he read it, but she was told that people did not believe she was the author.

Mr. Combs’s lawyers have described Ms. Ventura’s attempt to sell the book rights as “extortion” in court papers. Ms. Ventura decided to ask for $30 million without having done research about book payments, she testified, but she thought that number would get his attention.

Olivia Bensimon contributed reporting.

The term first came to public awareness in November 2023, when the singer Cassie filed a lawsuit accusing Sean Combs, her onetime boyfriend and record label boss, of years of sexual and physical abuse: “freak-off.”

According to the suit by Cassie, who was born Casandra Ventura, this was what Mr. Combs called the highly choreographed sexual encounters that he directed “to engage in a fantasy of his called ‘voyeurism.’” They involved costumes, like masks and lingerie. “Copious amounts of drugs,” including Ecstasy and ketamine. The hiring of male prostitutes. Mr. Combs watching and recording the events on a phone while he masturbated.

Freak-offs have become a central part of the government’s case, which charges Mr. Combs with sex trafficking, racketeering conspiracy and transportation to engage in prostitution. Mr. Combs has pleaded not guilty, and his lawyers have strongly denied that any of his sexual encounters with women were not consensual.

In much-anticipated court testimony this week, Ms. Ventura — who is visibly pregnant with her third child — described the freak-offs in sometimes excruciating terms. During hours of testimony on Tuesday, she cried and occasionally dabbed her eyes with tissue.

The first freak-off happened when she was 22, when Mr. Combs hired a male stripper from Las Vegas to come to a home that Mr. Combs was renting in Los Angeles, she testified. Ms. Ventura said she wore a masquerade-style mask and provocative clothing from a “sex store,” and that she and the man took Ecstasy and drank alcohol before they had sex and Mr. Combs watched.

The freak-offs “made me feel worthless,” Ms. Ventura testified, “like I didn’t have anything else to offer” Mr. Combs.

Freak-offs soon became nearly weekly occurrences, Ms. Ventura testified. They took places in homes and hotels across the United States and in international locales like Ibiza, a Spanish island; Mr. Combs had his employees make travel arrangements for the men to come to him and Ms. Ventura — a key point in the government’s case for sex trafficking. They also became more elaborately staged, with candles and studio-style lighting, and Ms. Ventura said she would sometimes take an entire day to prepare herself for them — Mr. Combs controlled that too, she said, down to the color of her nails.

She testified that she took part in the events partly because she wanted to make Mr. Combs happy. “When you’re in love with someone you don’t want to disappoint them.”

But she also said she feared his violence if she refused, and recounted episodes of him beating her. When Mr. Combs became angry, she said, “His eyes go black. The version of him that I was in love with was no longer there.”

The events drained her, she said, and it sometimes took days to recover.: “The freak-offs became a job where there was no space to do anything else but to recover and just try to feel normal again.”

The videos Mr. Combs made, she said, became “blackmail materials” that pressured her to agree to participate, for fear videos could be released on the internet, she testified.

Fueled by drugs, the freak-offs could last from 36 hours to four days, Ms. Ventura testified. They also became more “humiliating,” she said: Mr. Combs would direct her and the men on sexual positions, and he would order them to continually apply baby oil to keep themselves “glistening.” Blood was left on bedding because Ms. Ventura had to perform while menstruating, she said. There was also urine, as Mr. Combs sometimes told the men to urinate into her mouth while she lay on the floor — she could end it only by holding her hands in the air and hoping Mr. Combs would tell the man to stop.

In her testimony, Ms. Ventura said that a freak-off was underway in March 2016 at the InterContinental Century City hotel in Los Angeles, where a hallway security camera captured her trying to take the elevator before Mr. Combs assaulted her and dragged her away.

The freak-offs, she said, continued until she finally left Mr. Combs in 2018. But the government contends that another victim, who will be testifying under the pseudonym Jane, had freak-offs with Mr. Combs from 2021 until his arrest last year.

Before November 2023, Casandra Ventura was known to pop music fans as Cassie, the singer behind “Me & U,” an R&B hit built on a simple synth hook that peaked at No. 3 on the Billboard Hot 100 in 2006. Her debut album, which also arrived that year, was praised by critics and reached No. 4 on the Billboard 200.

While she was tipped as a next big thing after that early success, she struggled to advance in the music industry. Her anticipated second album never arrived.

Ms. Ventura had long been linked to Sean Combs. She met him when she was 19, and he was the head of her record label (she signed a 10-album deal with Bad Boy in 2006). He was also her romantic partner for more than a decade, starting around 2007.

The pair were routinely seen in public, on red carpets and at awards shows. Ms. Ventura released a few singles and, eventually, a 2013 mixtape. But behind the scenes, she said in a lawsuit filed in the fall of 2023, she was struggling.

Her suit accused Mr. Combs of rape, and of repeated physical abuse over about a decade. “After years in silence and darkness,” she said in a statement at the time, “I am finally ready to tell my story, and to speak up on behalf of myself and for the benefit of other women who face violence and abuse in their relationships.”

Mr. Combs strongly denied all the allegations, and his lawyer said the suit was “riddled with baseless and outrageous lies.” The sides resolved the suit in one day with an eight-figure settlement, but it helped start the federal investigation that led to Mr. Combs’s arrest nearly a year later.

Ms. Ventura, 38, last released music in 2019, via her own Ventura Music label. That year, she married the personal trainer, wellness consultant and sometime actor Alex Fine, who has been watching her testimony from the courtroom. She has taken the stand while pregnant with the couple’s third child.

The government’s case against Sean Combs comes down to a five-count federal indictment that accuses him of creating a criminal enterprise — called the “Combs enterprise” — to sexually abuse women and to commit other acts of violence against them over more than a decade.

The government has accused him of coercing four women into sex. In court papers, prosecutors have referred to the women only as Victim-1, 2, 3 and 4.

Count 2, sex trafficking by force, fraud or coercion: This count concerns Victim-1, Casandra Ventura, Mr. Combs’s longtime girlfriend and the R&B singer known as Cassie. Mr. Combs lost a bid to keep all footage of his 2016 hotel assault on Ms. Ventura out of the trial, and she is expected to testify in court under her own name.

Count 3, transportation of Ventura and “commercial sex workers” with the intent they engage in prostitution.

Counts 4 and 5 accuse Mr. Combs of similar crimes involving Victim-2, who has not been identified publicly and is expected to testify under a pseudonym.

At trial, Sean Combs will be represented by a large and varied defense team — one that has grown even larger and more varied in recent days.

Since early in the government’s investigation, Mr. Combs has retained Marc Agnifilo and Teny Geragos of the firm Agnifilo Intrater.

Mr. Agnifilo is a longtime criminal defense attorney who has represented high-profile figures like the former pharma executive Martin Shkreli; Keith Raniere, the leader of the Nxivm sex cult; and Dominique Strauss-Kahn, the former managing director of the International Monetary Fund, who in 2011 was accused of sexually assaulting a hotel maid in New York. (The case against Mr. Strauss-Kahn was dismissed before a trial.) Along with Karen Friedman Agnifilo, his wife, Mr. Agnifilo is also part of the defense team for Luigi Mangione, who has been charged with murder in the killing of a health care executive.

In and out of the courtroom, Mr. Agnifilo has been perhaps the strongest voice in Mr. Combs’s defense. At a hearing last month, he reiterated the defense’s argument that Mr. Combs’s “freak-offs” — sexual encounters that the government contends were coerced — were consensual, with Mr. Combs’s ex-girlfriend Casandra Ventura a willing participant. “Call it ‘swingers,’ call it whatever you will,” Mr. Agnifilo said.

In media interviews, he has called the case an “unjust prosecution” and said that Mr. Combs is “an imperfect person but is not a criminal.”

Mr. Agnifilo was a longtime lawyer at the firm Brafman & Associates but left last year to help start Agnifilo Intrater. With him, he brought Ms. Geragos, whose father is Mark Geragos, the celebrity lawyer who has represented Mr. Combs in the past. Ms. Geragos has also spoken publicly about the case, including in a series of TikTok videos that she posted before Mr. Combs was arrested in September.

The team also includes Alexandra Shapiro, a prominent appellate court lawyer at the firm Shapiro Arato Bach who was once a prosecutor in the U.S. Attorney’s Office for the Southern District of New York, which is prosecuting the Combs case. She graduated from Columbia Law School and was one of the first clerks for Justice Ruth Bader Ginsburg at the Supreme Court. She also wrote a novel, “Presumed Guilty.”

Ms. Shapiro is widely recognized for her success rate at trial and on appeals. “If you want to maximize your chances of either prevailing at trial or on appeal against the S.D.N.Y., then you should call Alexandra Shapiro (if you can afford her),” the legal newsletter Original Jurisdiction wrote last year.

Given her specialty, Ms. Shapiro may be keeping a close eye during the trial on any issues that might be useful if the defense appeals a verdict.

Mr. Combs’s defense also includes Jason Driscoll of Shapiro Arato Bach and Anna Estevao of Harris Trzaskoma.

In the last few weeks, Mr. Combs has added several other lawyers.

Most prominent is Brian Steel, who defended the rapper Young Thug in a long-running racketeering trial in Georgia. Young Thug, whose real name is Jeffery Williams, pleaded guilty to participating in criminal street gang activity, and was released with time served. But Mr. Steel — who was recently profiled in The New Yorker — drew wide notice, in legal circles and beyond, for a courtroom showdown where he accused a judge of improperly meeting with a witness. He was held in contempt but later vindicated when the judge was ordered to recuse himself from the case.

Mr. Combs’s team has also recently added Xavier Donaldson, a New York lawyer whose LinkedIn profile describes him as “litigator, professor, speaker, crisis manager,” and Nicole Westmoreland, who represented one of Young Thug’s co-defendants in his trial.

In April, Mr. Combs’s legal team asked for a two-month delay of the trial to consider what it said was newly produced evidence by the government. The judge denied the request, noting that Mr. Combs had four law firms working for him, giving him ample resources to prepare.

Since then, Mr. Combs has added two more.

At the opening of jury selection last week, Judge Arun Subramanian, who is overseeing the Sean Combs case, made an observation about a list shown to prospective jurors that contained the names of celebrities that may come up at trial.

“I read through the people and places list, which is several pages long,” Judge Subramanian said at the beginning of the hearing. “I felt like I was reading an appendix from ‘The Lord of the Rings.’”

It was an unusual moment of levity during a serious criminal case — and a rare glimpse into the candid thoughts of Judge Subramanian, who has been a federal judge for only two years but is presiding over one of the most high-profile criminal trials in the country.

Nominated to the bench by President Biden in 2022, and confirmed by the Senate in March 2023, Judge Subramanian was born in Pittsburgh in 1979, to parents who emigrated from India in 1970.

After attending Case Western Reserve University, he earned his law degree from Columbia in 2004. He began building an impressive legal résumé, with clerkships under two federal judges in New York as well as under Justice Ruth Bader Ginsburg at the Supreme Court. In 2007, he joined the law firm Susman Godfrey, and four years later, at age 31, became its youngest partner.

At Judge Subramanian’s confirmation hearing in late 2022, Senator Chuck Schumer, Democrat of New York, called him a “steadfast consumer protection expert” and said that his cases as a lawyer included defending victims of trafficking and child pornography. Judge Subramanian also developed a specialty in bankruptcy litigation.

In addition to overseeing the Combs criminal case, Judge Subramanian has been assigned the antitrust lawsuit against the concert giant Live Nation, which owns Ticketmaster. In that case, which was filed last year and has a tentative trial date in 2026, prosecutors have called for a breakup of the company, which is by far the largest power in the live entertainment world.

He is also a judge who values efficiency in his courtroom. During jury selection for Mr. Combs’s trial, Judge Subramanian asked the prosecution and the defense to let him know when they needed to take breaks, because if they didn’t, he would “just keep going until we reach the finish line.”

“As you will come to see,” he said, “I’m a machine.”

Judge Subramanian is the first person of South Asian descent to be a judge in the Southern District of New York. “My father grew up in a small village,” he said at his confirmation hearing. “One generation later, his son is sitting before this honorable committee. That is the American dream.”

At a speech last year to Columbia Law alumni, faculty and students, he said that as “the new kid” on the bench, he hosted the first karaoke event in the Southern District’s 235-year history. “I did not know,” Judge Subramanian remarked, “that there was so much enthusiasm for karaoke on the Mother Court.”