Photo credit: AP

Hundreds of protesters in Philadelphia have marched through the city for a second night, demanding racial justice after police fatally shot a black man. Demonstrators marched to a city police station while officers lined up behind metal barricades.

The family of the victim, Walter Wallace, 27, say he was suffering a mental health crisis when officers opened fire on him. Police say they shot him because he would not drop a knife he was holding.

Police said as of Tuesday afternoon, at least 91 people had been arrested in relation to the unrest. Looting — separate from the protests — was reported Tuesday night, particularly in Port Richmond.

Of the 91 people arrested, 11 were charged with assaulting police, 76 were charged with commercial burglary and three were charged with failure to disperse, she said.  There are also “several” ongoing investigations.

A video emerged purportedly showing the moments leading up to the shooting. It showed officers pointing their guns at Wallace as he walks in the street and around a car. He walks toward the officers as they back away from him in the street, guns still aimed at him.

They yell at him to put his knife down. The two officers then fired several shots and Wallace collapses in the street. A woman runs up to him screaming while several bystanders then approach him.

It is unclear in the video if he had a knife. Witnesses said he was holding one.

Wallace was hit in the shoulder and chest. One of the officers then put him in a police vehicle and drove him to a hospital, where he was pronounced dead a short time later.