BOSTON -- Jessica Herrera's family watched with tears in their eyes as their daughter's ex-boyfriend stood accused of strangling the 25-year-old. Just months before, Herrera told police she was punched, slammed and choked by Ashley Fernandez. Five days before his assault trial, Fernandez allegedly killed Herrera.

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Lesley Cheremond was also awaiting trial on charges of domestic assault and battery when he allegedly killed his ex-girlfriend, Norma Dorce-Gilles. Her body was found two weeks later in the trunk of her car.

Melissa Santiago , 29, was allegedly killed by her boyfriend, Jose Torres. Her four children were home at the time.

"It had to take killing my sister for him to be behind bars right now," said Stephanie Santiago. "He should have been there a long time ago."

Once a batterer gets into the court system, the assumption is a victim would be safer. But Team 5 Investigates learned it can actually be the most dangerous time and, in some cases, deadly.

"With a batterer, he's very likely in many cases to escalate his abusive behavior, his terror tactics at that point," said David Adams, Director of Emerge, a Batterer Intervention Program.

For two years Judge Sydney Hanlon ran the areas only domestic violence court. She's considered an expert in these cases.

"They carry probably the greatest possibility for lethality or fatal violence of any cases that we see," said Hanlon. "They carry the greatest possibility for recidivism."

"What happens at arraignment is essential, " said Assistant District Attorney Sylvia Rudman. "Once they are on on the street, it's more difficult."

Prosecutors can ask for dangerousness hearings to keep batterers behind bars. But they are used infrequently. In one county last year, only 132 hearings were requested, out of nearly 2,700 cases.

Judge Hanlon said she doesn't see many requests in her Dorchester court.

"In this court, not very often. I wonder why they don't," said Hanlon.

Part of the reason is that victims are reluctant to testify, something required under at 2005 Supreme Court ruling. Team 5 Investigates learned more than half of domestic violence cases are dismissed each year, statewide.

These dismissals are almost always because people are unwilling to cooperate at trial," said Judge Hanlon.

"One of the struggles with domestic violence cases is getting our victim on board," said Rudman. "That is either because there is low self esteem or they are afraid," she said.

Few perpetrators get help. Five years ago judges sent twice as many people to batterer intervention programs than they did last year.

"None of the killers that I know of in the past two years have been referred to batterer intervention programs," said Adams. "And so the courts for the most part are not using the programs."

Desperate for solutions, a group of police, prosecutors, social service workers, and victim advocates meet twice a month in New Bedford to keep tabs on troubling cases.

"We are trying to target the most high at risk of imminent physical danger or death," said Sgt. Pam Mello of the New Bedford Police.

The group's efforts have paid off, with an increase in dangerousness hearings, incarcerations, and victim testimony. But only seven communities in Massachusetts have these programs.

"I think they should be mandated," said Rudman.

Stephanie Santiago said she wished her sister had a team on her side. They might have reminded the court that her alleged killer, Jose Torres, had two prior domestic violence charges against other women. He might not have been out on the streets.

"They should have done something the first time they saw his record," said Santiago. "The first time that he put his hands on somebody, they should have known. It's too late for my sister."