ST. LOUIS • The three men accused in the death of Patrice Thimes all had been arrested in the months before she was killed by a stray bullet in a St. Patrick's Day shootout.

But they remained free because police and prosecutors could not build strong cases against them.

Ronnie Mottley, 18, Bernard L. Dorris, 19 and Sheltkeem Brown, 18, all of north St. Louis County, have been charged in the killing of the sister of St. Louis jazz singer Denise Thimes.

Police records obtained by the Post-Dispatch for city criminal cases involving the three men reveal allegations of violence, drugs, guns and stolen cars.

Mottley, who has the most serious criminal history of the three, was arrested several times in recent years, including in three assault cases, records show. But Mottley was released when witnesses in those cases refused to talk to police.

The no-snitch code on the streets is one police say is one rooted in fear of retaliation and antagonism for authority. It's a culture that often produces few strong leads and unwilling victims who prefer to settle feuds on their own.

"This cycle of retaliation oftentimes goes unchecked until there's a very tragic incident," said St. Louis Police Chief Dan Isom. "There's a certain amount of risk to standing up to (suspects). We need cooperation from citizens. That's vital, and it demonstrates it in this case."

After Patrice Thimes, 39, was killed when she unwittingly drove in to a gunbattle on Page Boulevard last month, witnesses did come forward to identify Mottley, Dorris and Brown as the shooters.

Thimes' fiancé, Gregory Bell, says the three should have been behind bars for earlier incidents. "If they had multiple charges on these guys, why were they even walking the streets?" said Bell, 45, of St. Louis.

Mottley is the only suspect in Thimes' killing with arrests in violent incidents. He was arrested in three separate assault cases in 2009 and 2010.

When Thimes was killed, Mottley was on probation for two drug convictions.

On Dec. 1, Mottley and another man were shot in the 1700 block of Billups Avenue, and police are still investigating.

The other two suspects in Thimes' killing have less serious criminal records. Dorris was arrested in October on suspicion of drug possession, but prosecutors said they lacked the evidence to charge him. Dorris has no convictions in Missouri.

Brown was released after police arrested him during a traffic stop in November on suspicion of possessing marijuana and crack cocaine. Police sought drug trafficking charges, but prosecutors filed lesser charges of drug possession.

Six weeks after Thimes' death, it is unclear who fired the shot that killed her, and police refuse to discuss cases once prosecutors file charges.

Bell is rearing the 5-year-old daughter he had with Patrice Thimes alone. He said he believes his fiancée would still be alive if witnesses had helped police and prosecutors in previous cases.

"They've got to live with Patrice's death also," Bell said. "If the individuals had come forward prior to what happened to Patrice, we wouldn't be in this situation."