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Police: Man charged in girlfriend's stabbing death

Marvin Williams accused of killing woman in her Moncrief home

JACKSONVILLE, Fla. – A man accused of stabbing his girlfriend to death Monday in their Moncrief area home was tracked down by police Wednesday and arrested, according to the Jacksonville Sheriff's Office.

Police said that within an hour of posting to social media asking for help to find Marvin Williams, several tips came in that he was working construction at Baptist South.

Officers responded to the area, and Williams ran off, police said.

He was chased to the parking lot of a Courtyard Marriott on Old St. Augustine Road and was arrested there without incident, police said.

He was denied bond Thursday at a first appearance hearing. He'll be back in court Feb. 15.

Williams is accused of fatally stabbing his live-in girlfriend, 61-year-old Cassandra Valentin, who was found dead Monday during a welfare check at their Frank E Avenue home in the Moncrief neighborhood, police said.

Williams' sister, who declined to give her name, told News4Jax that the welfare check was prompted by a text message and a voice recording Williams sent to their other sister that made family members concerned for Valentin's well being.

"She put the recording on, and I'm not going to get into what was said on the recording, but that made me go to check over there at the house," the sister said.

Williams' sister said the two had been planning a June 30 wedding.

"I don't know what happened," she said. "I don't know what could have led to this."

Detectives said right after finding Valentin's body that they suspected foul play, but did not say until Wednesday how she died.

Police thanked the public for their help in tracking Williams down quickly Wednesday.

"We can't thank you enough for working with us to make a difference," police said in a tweet.

Williams' sister said family members had tried to get him to turn himself in to avoid potential harm.

"I just wish they would tell what happened or I can talk to him at least and find out what happened," she said.

Valentin, who'd had a cosmetology license since 1988, was called "Sandy" by her loved ones, who described her as a calm, sweet woman who was a good friend.

Her family told News4Jax that Valentin had been dating Williams since 2004.

News4Jax found that Williams was arrested in 2012 for domestic battery on Valentin after he punched her repeatedly in the face, according to police. The charge was later dropped.

Valentin obtained a temporary domestic violence injunction against Williams, but it was dismissed weeks later. 

In 2013, Williams was arrested for sexual battery, aggravated battery, felony domestic battery and false imprisonment. The arrest report is redacted because of the sexual assault, but in another domestic violence injunction petition, Valentin identifies herself as the victim in that case. There was a plea deal, in which Williams pleaded guilty to felony domestic battery and false imprisonment, and was sentenced to four years of probation.

In 2017, Williams violated his probation by not continuing his psychosexual counseling. His probation was extended to 2020. Several months later, Valentin asked for the injunction to be modified to no violent contact. In that request, she wrote that “I believe he is a different person and I no longer fear for my life. I have completely forgiven him and would like to communicate with my friend again without violence.”

Relatives admitted the couple had a history of abuse but said they loved each other and were inseparable.

Williams' sister said she had hoped it would turn out differently for the couple this time. 

It did end differently, just not happily.

"Nobody knows what happened but Cassandra, Marvin and God," his sister said.