The D.C. Council vowed Thursday to review accusations that the Metropolitan Police Department failed to investigate at least 170 sexual assaults in a three-year span, even as those charges prompted blistering critiques from the city's top cop.

Human Rights Watch leveled the allegations in a 196-page report published Thursday that also said "police re-victimized survivors by treating them callously and skeptically, discouraged sexual assault survivors from reporting their assault or getting a forensic exam and in some instances threatened them with prosecution for false reporting."

Police Chief Cathy Lanier, who tangled with the organization about the report ahead of its release, hammered the assessment as the defective production of a publicity-hungry group that would undermine the department's efforts to stem assaults.

"The allegations in this report serve to undo all the progress that we have made," Lanier said. "This report will make some of our most vulnerable victims here in the District of Columbia, the victims of sexual abuse, even more reluctant to report their abuses to police."

And in a December letter, Lanier accused Human Rights Watch of a "desire to draw public attention to themselves" and possessing "self-serving energy."

The organization told Lanier in response that it had "rarely encountered -- at least within the United States -- the type of hostility and defensiveness evident in your letters."

Despite Lanier's dismissal of the report's findings, Ward 6 Councilman Tommy Wells, the chairman of the council's judiciary committee, said he wants more answers.

"The report brings up very serious allegations that go straight to the confidence of our citizens about MPD's ability to handle sex abuse crimes in a way that is both thorough and competent," Wells told The Washington Examiner on Thursday. "I certainly want to hear from the chief and the mayor on their rebuttal, but I'm taking this report very seriously."

Wells, who said he may propose legislation in the aftermath of his review, said he would schedule his hearing after learning more about the status of a Lanier-requested evaluation of MPD practices by the U.S. Department of Justice.

Lanier was adamant that her department's handling of sex crimes has been acceptable and pointed to statistics that show sexual assaults have risen in the District as evidence that the city's outreach efforts have encouraged more victims to report attacks.

"Between 2010 and 2011, cases of sexual abuse increased by 23 percent. In 2012, reports of sexual abuse increased by 51 percent over the previous year," Lanier said. "That tells me that we are doing something right and that more victims are coming forward to report their crimes."

Kristopher Baumann, the chairman of the city's police union, assailed the department's response to the report as typical, but he said Wells' review could ultimately bolster Lanier's argument.

"This is an agency with no oversight, yet when anyone peeks behind the curtain, it's an all-out attack against the people trying to bring forward the problems," Baumann said. "The more sunshine, the better. If there are problems, they need to be fixed. If there are not problems, then the department will be vindicated."