Hawaii’s county police departments are making progress — albeit slowly and haltingly — in handling their huge backlog of untested sexual assault evidence collection kits, otherwise known as rape kits.

It’s an encouraging development that did not come easily. After intense lobbying by victims rights groups and action by the Legislature, the police departments on Maui, Kauai, Hawaii island and Oahu began to develop inventories of their untested rape kits and get them tested.

These efforts need to continue and accelerate, and become part of normal police procedure.

The kits contain DNA and other evidence provided by victims who may endure several hours of invasive head-to-toe medical examinations. While the evidence may not be needed for the case at hand, the data from properly tested kits can be uploaded into state and federal databases, providing evidence to identify serial rapists, strengthen a prosecutor’s case, and in some cases, exonerate the wrongfully accused.

Furthermore, an increased emphasis on investigating sexual assault cases, using sophisticated DNA tools, may encourage victims who might otherwise remain silent to speak out.

In short, testing the rape kits serves justice; leaving them on a shelf does not.

Hawaii is not the only state to recognize the important role rape kits play in handling sexual assault crimes. High-profile campaigns to reduce the backlog of untested rape kit — estimated at between 100,000 to 400,000 kits nationwide — have yielded positive results.

In New York City, the city’s rape arrest rate rose from 40 percent to 70 percent after it began testing every kit, according to news reports. Detroit and Cleveland have launched aggressive efforts to clear their backlogs; more than 600 potential serial rapists were identified in Detroit.

On Friday, President Barack Obama signed the Survivors’ Bill of Rights Act of 2016, which addresses how rape kits are handled in federal criminal cases.

Among other things, it gives survivors the right to receive the results of rape kit tests and to petition to preserve the evidence beyond the mandatory statute of limitations.

It does not, however, contain a mandate to test rape kits.

This year, Gov. David Ige signed into law Act 207, which requires police departments to provide inventory reports on untested rape kits to the state attorney general by this Sept. 1. The AG will use the inventories to develop a report to the Legislature that is expected to provide a clearer picture on how the kits should be handled, including protocols for testing the kits and notifying victims about testing results.

The AG’s report should help lawmakers and law enforcement officials clear away some of the brambles that have hindered the proper handling of rape kits. But it will take a sincere commitment from the police departments to ensure that progress is made. Only Maui met the deadline for filing its inventory report, and progress in testing the kits remains painfully slow.

The law allocated $500,000 in state funds to provide for testing at least 500 kits and “associated victim support services” by the end of the year. HPD has tested 137 kits and intends to have 500 tested before the year’s end. But HPD started with a backlog of more than 1,500 units. On the neighbor islands, more than 600 kits remain untested.

For the sake of justice and all victims of sexual violence, Hawaii’s police departments will need to work more aggressively to improve those numbers.