D.C. Police Chief Cathy L. Lanier, shown in Febuary. (Marvin Joseph/The Washington Post)

D.C. Police Chief Cathy L. Lanier on Thursday rebuffed calls to make video captured by police body cameras open to public review, saying redacting sensitive material would lead to “potentially staggering” costs and still not ensure the privacy of those seen on tape.

Lanier’s testimony before the D.C. Council’s Judiciary Committee was met with hostility by the head of open government for the city’s Board of Ethics and Government Accountability. Traci Hughes called Mayor Muriel E. Bowser’s proposal to exempt all footage from public-records laws “completely counter to the executive’s professed aim of a more inclusive and transparent government.”

The exchange highlighted the schism over the Democratic mayor’s proposal to outfit all 2,800 D.C. patrol officers with body cameras and the challenge of settling on guidelines for who would be able to view the videos.

A day before Thursday’s hearing, Kenyan R. McDuffie (D-Ward 5), the committee’s chairman, said he would not support Bowser’s plan to redact all footage.

Testifying before McDuffie, however, Lanier pressed the administration’s case. She arrived armed with an elaborate video staging what she described as a typical police dispatch to a domestic disturbance. The production was intended to show how much personal information could be released if all police videos are public.

In the video, a child actor calls 911 and says that her father has been drinking. An officer’s video shows the faces of family members, medication, bills, personal photos and even curtains with sailboats visible in the frame.

Lanier noted that the distinctive curtains alone would be enough for “anybody who has been in that home” to identify the family.

Lanier dismissed the practices of other police departments, including Seattle’s, where fuzzy versions of police videos are being posted to YouTube. She said that automated redaction software could ensure total anonymity only 90 percent of the time, which she called an unacceptable rate. Also, she said, department employees would still have to physically review each moment of video that is released.

Lanier instead laid out a proposal to treat body-camera footage akin to other police evidence. She said doing so would still increase police accountability because unredacted video could be accessed by prosecutors, city auditors, the D.C. inspector general and the Office of Police Complaints.

Members of the public, however, would be able to view the video only in limited circumstances. Those would mostly include instances in which people who feel victimized by police are considering initiating or have initiated legal action against the department.

Lanier also proposed that in instances of great public interest, “the mayor, in consultation with the police chief and prosecutors, may release . . . video that would serve the public’s best interest.”

During the hearing, several outside experts urged the city to release more information than it retains, saying the nation is facing a watershed moment in the realm of police reform.

As one of the largest U.S. police departments to embrace body cameras for all patrol officers, the District’s policies could be looked to as a model nationally, some warned.

Critics also urged the city to consider the likelihood of cyberattacks on the police videos the District might amass and to study whether the perception that an officer’s conduct changes when cameras are worn is true.

Lanier said she firmly believes that the cameras can improve accountability even without disclosing all of the footage. She said she would support a policy of requiring officers to wear their cameras at almost all times.

The chief added that officers in the District as well as across the nation “recognize that the public perception of policing is at a low point.” But, she added, a “grand gesture” of releasing all body-camera footage wouldn’t change public perceptions about law enforcement. “Police are going to need to restore trust one interaction at a time,” she said in prepared remarks submitted to the committee.

During her testimony, Lanier urged McDuffie to approve funding for the body cameras and set up guidelines at a later time. Others said moving forward with a contract before it’s clear how long the city will want the video retained and how easily it must make it available to the public could allow the department to restrict access to the video preemptively.

McDuffie is scheduled to mark up the portion of Bowser’s budget regarding body cameras next week.

“I urge the council to pass the budget that will allow us to use this tool, but in a manner that allows us to protect the privacy of the people who call on us for assistance, not public scrutiny,” Lanier said.