Families of people killed by Boston police confronted officers and Suffolk County District Attorney Dan Conley last night at a forum in Roxbury.

Map: 71 Police-Involved Deaths In Massachusetts From 2004 - 2014

An audience of about 100 people, mostly African Americans, said things like, “That’s not true,” and, “That’s a lie,” as police and Conley gave presentations about the process of investigating fatal shootings by police.

In a rare face-to-face confrontation, the mostly African-American audience sharply questioned the fairness of investigations into officer-involved shootings. Some families of those killed said they felt like police had given them the brush-off.

One audience member told Police Superintendent-in-Chief William Gross that Boston’s department is burdened with a legacy of racism and disrespect of the African-American community.

“How can you really say honestly that you’re going to do something, that you have the ability to do something, to change a system that’s clearly, obviously, rotten to the core?” asked Rev. Jermeal Williams.

Gross, who is African American, said things could change, because they have before.

“We have to talk and we have to listen to make the changes," he said. "Now in this time, in this era, you as a black man can express your opinion to us and do so without worrying about dogs, hoses, being beaten. And don’t think for a minute, folks, that I’ve forgotten where I came from. So let’s work on it.”

Conley said he was there to build trust and explain the current system, not defend it. Confronted by one of the families of the who said they had been waiting more than a year for results of an investigation, Conley acknowledged the process should move quicker.

Conley said his office is a check on police, and his investigators don’t have a separate process of justice for officers. Conley said in the last decade, Boston police have fatally shot eight people, and all were armed. Conley said he decided against criminally charging the officers in those cases. But his office has prosecuted 17 other officers over the last 10 years for various crimes.