Protests continued in Philadelphia as more details emerged on Wednesday about the police killing of 27-year-old Walter Wallace after his family had called for medical assistance when he was having a mental health crisis. Civil rights campaigners fiercely questioned the way police departments handle people suffering a mental health problem, not just in relation to the shooting of Wallace but across the US. After the killing, hundreds took to the streets of the Pennsylvania city chanting Wallace’s name and demanding racial justice and equality. On Tuesday, peaceful protests were followed by clashes with police and some vandalism. More than 90 people have been arrested and about 50 police officers were injured in confrontations with protesters and vandals, authorities say. Protests continued on Wednesday evening, ahead of a 9pm curfew. Relatives of Wallace on Wednesday called for calm. Joe Biden and Kamala Harris, the Democratic nominees for president and vice-president, issued a statement about Wallace’s killing, saying: “Our hearts are broken for the family of Walter Wallace Jr, and for all those suffering the emotional weight of learning about another Black life in America lost.” Relatives described Wallace as suffering from a mental breakdown. However, their call for help, in which they requested an ambulance, not police, ended in a deadly confrontation with law enforcement after reports that the man had a knife. Relatives said on Wednesday that Wallace had bipolar disorder and was in the midst of a crisis when he was killed by police, reported CNN. His father, Walter Wallace Sr, said the incident “could have been dealt with in a different way”. The officers, he said, “could have called a superior to handle the situation”. Wallace Sr also called for peace, and urged people to pray for his family. “All this violence and looting. I don’t want to leave a bad scar on my son and my family with this looting and chaos stuff,” Wallace Sr told CNN. “Stop this. Give my son a chance. And the family, we’re decent people.” He added: “It’s an SOS to help, not to hurt.” Reggie Shuford, the executive director of the ACLU of Pennsylvania, said Philadelphia was “overdue for a reckoning with the brazenly violent and abusive behavior in its police department” and that it has a “long history of brutality against city residents, particularly against Black Philadelphians”. “In the days ahead, we expect full transparency from Commissioner Outlaw, the Kenney administration, and District Attorney Krasner’s office about this tragedy. While witnesses have stated that Mr Wallace was armed with a knife, video from the incident suggests that no one was in immediate danger when officers killed him,” he said in a statement. “State violence cannot be the answer to societal problems that deserve a fairer, more thoughtful, and more compassionate approach.” He called for cities around the US to divest in police and instead invest in mental health services that he said might have “prevented Mr Wallace’s killing”. He said in 25-50% of police killings, the victim was undergoing a mental health crisis. “There is a better way to handle these incidents. But instead, yet again, we see police officers fail the people they are sworn to protect. Again and again, their answer is violence and death.” The killing became the latest flashpoint in the US amid months of largely peaceful protests that reinvigorated the Black Lives Matter movement against structural racism and police brutality. Police have said that Wallace Jr was wielding a knife and ignored orders to drop it before officers fired shots on Monday afternoon. But his parents said on Tuesday night that officers knew their son was in a mental health crisis because they had been to the family’s house three times on Monday. Catherine Wallace, his mother, said one of the times, “they stood there and laughed at us”. The Wallace family’s attorney, Shaka Johnson, said the dead man’s wife, Dominique Wallace, was due to give birth this week. Two of Wallace Jr’s nine children briefly spoke at a news conference late on Tuesday, along with his mother and father. “When you come to a scene where somebody is in a mental crisis, and the only tool you have to deal with it is a gun … where are the proper tools for the job?” Johnson said, arguing that Philadelphia police officers were not properly trained to handle mental health crises. Johnson said Wallace Jr’s brother had called 911 to request medical assistance and an ambulance. Johnson added on Wednesday morning that the officers did not have Taser stun guns and were not equipped to deal with a person in mental decline and that police training more generally needed reform, so that cops and communities were not pitted in “a lose-lose situation”. Police said the shooting had occurred just before 4pm as officers responded to a report of a person with a weapon. Video footage of the incident shows multiple shots being fired at Wallace.