Twenty-three states use such devices, and have seen violence decrease. In Connecticut, there have been virtually no domestic violence-related homicides in the counties that use these GPS devices since 2004, when the state started to use GPS trackers.

In a 2012 study, researchers from the University of Illinois at Chicago and Florida State University found that batterers who were required to wear a GPS device were less likely to violate a restraining order or try to harm the victim. The American Probation and Parole Association has also reported that better monitoring of offenders is effective in reducing violence.

Victims of domestic abuse are frequently blamed for not leaving their abuser, a response that profoundly ignores the fatal danger victims — and their families — face when they leave or attempt to leave. Currently, victims have few ways to protect themselves. Researchers at the University of Pennsylvania and the University of California, Los Angeles, School of Public Health found that one-third of victims were murdered within a month of obtaining a restraining order. Abusers often become more violent after a victim leaves, when a restraining order is issued or when they are released on bail.

Domestic abuse frequently follows a specific pattern of escalating violence, often the precursor to a victim’s murder, but batterers who repeatedly violate restraining orders usually face little to no punishment. Up to two-thirds of restraining orders are violated in domestic violence cases.

Firearms play a significant role in intimate partner homicide. But many states don’t effectively monitor whether a court order to surrender firearms was followed. In order to standardize the process, offenders who are ordered to hand in their firearms should be tracked and those who are noncompliant should be reported to the presiding judge.

Electronic monitoring raises some questions about an individual’s right to privacy. But the Supreme Court has ruled that electronic tracking is within the scope of the Fourth Amendment — and many state courts have declared that protecting domestic violence victims’ lives requires the use of electronic surveillance.

Critics have voiced concerns about the cost of GPS devices and their technical glitches, which can make an offender wrongly appear to be in violation of the terms of their release. But the benefits of tracking repeat domestic batterers, given the staggering rates of intimate partner homicide, far outweigh the limitations.

“Domestic violence homicides are among the most predictable, and therefore the most preventable, of all homicides because there are patterns that can be identified,” said Toni Troop, the director of communications and development for Jane Doe Inc.

Laura Aceves’s life could have been saved if her batterer had been tracked. Ms. Aceves was shot in the head, in front of her 4-month-old baby, by her ex-boyfriend, Victor Acuna-Sanchez, in Arkansas. Mr. Acuna-Sanchez was out on bail for multiple domestic assault charges.

Long before Ms. Aceves was murdered, Mr. Acuna-Sanchez terrorized her and repeatedly broke the conditions of his pretrial release. Three weeks before he killed her, he was arrested for violating a no-contact order. He was released the following day. Mr. Acuna-Sanchez was ordered to check in regularly with his probation officer, but never did. Arkansas law enforcement never bothered to follow up.

To help determine potential lethality of domestic abuse, Jacquelyn Campbell, a domestic violence expert and a professor at Johns Hopkins University, created a 20-question risk-assessment tool, but it hasn’t been put into practice nationwide. The tool should be used in each state to improve judges’ ability to assess when electronic tracking is needed.

Unchecked repeat offenders do not relent. They won’t stop until they kill their target. Heavier surveillance is necessary to halt them.

Misha Valencia (@newyork_writer) is a writer and clinician who specializes in treating trauma.

Follow @privacyproject on Twitter and The New York Times Opinion Section on Facebook and Instagram.