D.C. Council member Tommy Wells has called for a hearing about a report released on Thursday that says District police did not document or investigate at least 170 sexual assault cases. (Marvin Joseph/The Washington Post)

The chairman of the D.C. Council’s public safety committee plans to hold a hearing on a human rights group’s allegations that D.C. police failed to document and investigate at least 170 reports of sexual assault and that officers had bullied victims into not pursuing rape cases.

“This deserves a very cautious and thoughtful review to be sure we don’t respond with window dressing,” Tommy Wells (D-Ward 6), the new head of the committee, said Thursday. “We want to find a way to reassure people that have been victimized through sexual abuse that they have a government that will effectively respond to what they need.”

Thursday morning, New York-based Human Rights Watch officially released its 197-page report on the police department’s handling of sexual assaults. In an interview later, Wells said he had met with the report’s author and other representatives of the group earlier in the week.

Wells said that he has not set a date for a hearing and that he plans to meet first with D.C. Police Chief Cathy L. Lanier.

The chief has vigorously disputed the study’s methods and conclusions. In a statement Thursday, she said that “sweeping allegations that are not backed by facts undermine the credibility of HRW.”

Still, Lanier has announced changes that include revising the way reports are labeled to ensure they are properly investigated and launching an Internet site to encourage women who feel mistreated by officers to come forward. Lanier also ordered detectives to review hospital and police records to make sure every sexual assault complaint is accounted for and investigated.

Sara Darehshori, the author of the Human Rights Watch report, formally unveiled the findings at the National Press Club on Thursday. The conclusions had been known and debated for several days.

Each side says it has requested a review by the U.S. Justice Department — Lanier through a letter inviting federal investigators into her department; Darehshori through a meeting with officials earlier in the week. A Justice spokeswoman confirmed both requests but said no decision had been made.

To ensure the proper treatment of victims, Darehshori said, she wants advocates to accompany them during interviews with detectives. She said the problem isn’t departmental policies but rather “the practices of the officers” and a “police culture that tolerates the mistreatment of victims.”

In addition to the 170 missing cases, Darehshori said, 34 sexual assault reports were found in a nonpublic database labeled “miscellaneous” and “office report,” which she said are other ways of saying “case closed.” Police deny Darehshori’s assertion, but say that they no longer use those classifications for sexual assaults and that all such reports are now in the public case file.

The Human Rights Watch report contains lengthy summaries from as many as 15 women — representing a tiny fraction, police say, of the 1,500 sexual assaults investigated in the three years covered in the report — and a review of hundreds of hospital and police records.

According to the report, one woman told researchers, “The police told me they didn’t want to waste their time with me.” Another said, “They didn’t listen to me, they just made me feel completely ashamed of myself, they made me feel like I was lying or like I was too stupid to understand what happened to me.” And another said, “Reporting to the police was far more traumatizing than the rape itself.”

Lanier said she would like detectives to make a video record of police interviews with victims, which is done in many cities to preserve accounts and make sure stories remain consistent. But prosecutors are hesitant.

“While videotaping victims’ statements can be beneficial in some kinds of cases, we believe that the practice carries a risk of adding to the trauma and discomfort already felt by victims of sexual assaults,” said Kelly Higashi, chief of the sex offense and domestic violence section of the U.S. attorney’s office.