Columbia Police say witnesses of crimes coming forward to authorities with information could help them unravel unsolved cases. But they also understand, there could be a risk.

"I think there's a variety of reasons [why a person would not come forward to police]," CPD Lt. Matt Gremore said. "I don't think anybody wanted to be labeled as a snitch. It's a big part that we have to overcome."

Gremore also said he can understand someone not coming forward to police over a family member being threatened.

"I can understand it, but it does not stop the violence by doing that," Gremore said.

A witness intimidation guide written by Arizona State University outlines the different roles a witness may have within the community.

"Particularly in violent and gang-related crime, the same individual may, at different times, be a victim, a witness, and an offender," according to the guide. "Historically, witness intimidation is most closely associated with organized crime and domestic violence."

The guide says intimidation can include looks or gestures, threats of violence, physical violence, property damage or stalking.

Columbia Police are investigating multiple cases where they believe many witnesses saw a crime happen, but few people or none have come forward to authorities. A few of these cases include unsolved homicides.

On April 25, 2016, 24-year-old Garbrielle Rhodes was shot and killed at the Deerfield Apartment Complex on Sylvan Lane. At the time, neighbors told ABC 17 News, they saw "young people" running from the scene after shots were fired around 7:45 p.m.

"I think that there was a group of people that were with Rhodes when he was shot," Gremore said. "I think that those people know exactly what happened, and I think even the associates of those people would know exactly what happened based on having conversations about it."

Police believe the Rhodes homicide was likely sparked by an earlier shooting that day, where two people were hurt near the Interstate 70/Highway 63 connector. The three suspects from that shooting were quickly arrested at the Rhodes homicide scene about five hours later.

"We have criminals that exist, and silence is what protects them," Gremore said.

In 2021, Columbia Police Assistant Chief Jeremiah Hunter spoke to ABC 17 News about another unsolved homicide case. He said on Nov. 30, 2014, Columbia Police responded to the 1400 block of Illinois Avenue just before 2:30 a.m. More than 100 people were hanging out at an after-party.

"A fight ensued, a verbal argument ensued and everything, and soon after that, shots rang out and two people were hit, one being Rickie Dunn," Hunter said.

Both the Rhodes and Dunn cases involved multiple witnesses, but police have not been able to arrest anyone for their murders.

If a person is arrested and charged with murder, the prosecution can also face additional hurdles with witnesses.

Boone County Prosecuting Attorney Roger Johnson said the prosecution of a criminal defendant can depend on witnesses being willing to testify in a case.

"Usually when the state isn’t able to obtain the results we would hope, it’s because of lacking available witnesses," Johnson said. "A lot of people don’t realize that when we have a trial, we have to have witnesses we can physically put on the stand to testify about what happened."

Watch the latest Mid-Missouri Cold Case Files featuring the Garbrielle Rhodes case at 10 p.m. Wednesday on ABC 17 News.