Women who report sexual assault at the hands of their intimate partners don’t always cooperate with the criminal investigation. Because of fears for personal safety, or a desire to “put the incident behind her,” the help for detectives can slow down or disappear entirely shortly after the initial police response.

A new academic study of Los Angeles sexual assault investigations of husbands and boyfriends indicates that police may be able to urge more cooperation from victims, using some predictive models of domestic-violence dynamics.

“Due to the salience of victim cooperation in case outcomes, it is important to examine the conditions that surround the refusal to cooperate,” writes Eryn Nicole O’Neal, the author, of the Department of Criminal Justice and Criminology at San Houston State University. 

The group of 160 intimate-partner sexual assault cases were investigated by the LAPD in 2008, according to the study published in a recent edition of the journal Justice Quarterly.

The series of cases indicated that the women were more likely to assist investigators if they were married to the suspect, and if they had had been in a longer relationship. The alleged victims were also more likely to continue cooperating if they had been threatened during or prior to the incident, O’Neal writes.

But the collection of physical evidence at the earliest stages of the investigation is one of the most crucial factors.

“These findings suggest that any evidence collection potentially increases the likelihood that (intimate-partner sexual assault) victims will cooperate with police,” the study contends, “Victims receive subtle, yet powerful, messages regarding their worthiness through their interactions with legal authorities. Evidence collection may communicate to the victim that her case is being taken seriously, facilitating cooperation.”

A way to foster the increased diligence among primary investigators is to combat the “rape myth acceptance” phenomenon, O’Neal argues. That tendency to look for culpability on the part of the victims could hamstring investigations, she writes.

Other factors that could diminish the chances of resolving domestic rape cases are factors that cops could try to mitigate, she adds. Women often claims they want to put the case behind them, or they begin to blame themselves for the incident. Or the victim may recant out of fear, or they may even still be in the relationship – with all the added barriers that brings, like being denied access to a phone or transportation to follow up with detectives. Police understanding those factors, and trying to work around them, could mean more success in court.

“Research has long highlighted the barriers that (domestic violence) victims face when seeking help from the criminal justice system.” O’Neal writes. “It is necessary that law enforcement officers treat victims of intimate-partner sexual assault as (domestic violence) victims and acknowledge potential relationship-based barriers to cooperation.”