Bill Clinton said that aspects of his 1994 crime bill “cannot be justified” while campaigning for his wife Friday, one day after engaging in a heated exchange with Black Lives Matter protesters.

“It is true it had longer sentence provisions,” the former President told the audience at Penn State Behrend in Erie, Pennsylvania. “It is true that they led to some people going to jail for too long in ways that cannot be justified. And I went to the NAACP convention last year and said that and said it was way past time to change.”

Clinton sparked aggressive backlash on Thursday for defending the bill after a group of protesters accused him and Democratic presidential candidate Hillary Clinton of playing a key role in locking up blacks for minor drug offenses.

“I don’t know how you would characterize the gang leaders who got 13-year-old kids hopped up on crack and send them out in the street to murder other African-American children,” he told the protesters. “Maybe you thought they were good citizens, she didn’t. She didn’t.”

“You are defending the people who kill the lives you say matter,” he added. “Tell the truth.”

On Friday, he told the audience that his aim was to “vigorously defend” his wife and said that he was provoked by the protesters speaking over him.

“I realized I was talking past her the way she was talking past me,” Clinton said of one of the female protesters. “I know those young people yesterday were just trying to get good television and they did. But that doesn’t mean I was most effective in answering it.”

“I almost want to apologize for” my response, he added.

According to tweets from Erie Times-News reporter Sarah Stenem, Clinton framed the altercation as a learning experience.

. Billclinton: we cannot learn anything unless we listen #erielive — Sarah Stemen (@ETNstemen) April 8, 2016

.@billclinton: we’re all vulnerable to saying something we don’t like #erielive — Sarah Stemen (@ETNstemen) April 8, 2016

Both Clintons have faced criticism for the impact of the crime bill during the 2016 race. In February, a Black Lives Matter activist asked Hillary Clinton to “apologize for mass incarceration” and for referring to young black teenagers as “super-predators.”

Clinton said after the incident that she “shouldn’t have used those words” and wouldn’t today, and admitted during a March debate that parts of the crime bill were a “mistake.”