The city’s prompt release of the police bodycam footage depicting the fatal police shooting of Walter Wallace Jr. — with the cooperation of Wallace’s family — should be lauded. Its content cannot be.

The footage shows the horrifying spectacle of a Black man in the midst of a mental health crisis being shot by police less than a minute after their arrival, and the heartrending anguish of his mother and family members who witnessed Wallace’s killing.

Viewers will share this anguish, as well as the big unanswered question: Why? What turned the tide for officers who decided fatal force was the only way to handle a man who was clearly disturbed – and who had a history known to the department — who was carrying a knife but appeared to be walking aimlessly rather than aggressively? The footage shows at least two other people, including Wallace’s mother, trying unsuccessfully to intervene before Officers Sean Matarazzo and Thomas Munz started shooting.

» READ MORE: ‘You killed my son!’ City releases bodycam footage and 911 calls in Philly police killing of Walter Wallace Jr.

We do not know what was in the minds of the two young officers – one on the job for three years, the other for two years — but we can speculate what wasn’t: adequate training to deal with such a situation. Also not present was the aid of a behavioral health unit of the police trained to handle such situations, involving de-escalation rather than force.

Another key question: why better training of Philadelphia cops and policies related to use of force remain inadequate. Similar questions about force were raised during the post-mortem of police action during the protests over the George Floyd killing months ago.

But these questions have also been raised for years.

In 2013, with officer-involved shootings increasing, then-Commissioner Charles Ramsey requested assistance from the Department of Justice’s Office of Community Oriented Policing Services (COPS Office) to review the Philadelphia Police Department’s use of deadly-force policies and practices.

The resulting report in 2015 found “serious deficiencies in the department’s use-of-force policies and training, including a failure to maintain a certified field training program; deficient, inconsistent supervision and operational control of officer-involved shooting investigations and crime scenes.” It also called for improvement in and oversight and accountability.

» READ MORE: ‘Shoot him,’ officer said before firing at Walter Wallace Jr., lawyer says bodycam footage shows

The report calls police use of deadly force one of the defining issues of our criminal justice system. It is especially critical when it intersects with mental illness.

In fact, in the same year, a key report on the intersection of policing and mental illness was released by the Treatment Advocacy Center. It found that the mentally ill make up a disproportionate total of those killed in police encounters. The report maintains that the risk of being killed while being approached or stopped by law enforcement is 16 times higher for individuals with serious mental illness; and at least a quarter and up to half of police-involved shootings involve people with mental illness. Unfortunately, a program by the Justice Department to collect mental health information in cases of police shootings was suspended.

Society as a whole does not have a great track record adequately dealing with mental illness. That’s a situation worsened by budget cuts and shrinking supports for behavioral health, and has created a gap that we have unfairly expected police to deal with.

Among the remedies is a prompt investigation into the Walter Wallace death. We need many answers: Why a specially trained unit was not immediately dispatched to the Wallace call. Why young officers are not paired with more seasoned officers. Or why these officers were among those who didn’t have Tasers.

» READ MORE: I’ve had public mental health outbursts like Walter Wallace Jr. I’m alive because I’m white. | Opinion

What should emerge is a plan for overdue reforms that can improve policing – and its job of protecting people. What that must include is better recognition of the complexity of the problems that we rely on police to handle, which are not always criminal.

As the questions keep coming, so do the promises by the mayor and the police commissioner to review and make changes. City officials took the right step by releasing the bodycam footage and announcing on Thursday that the second phase of crisis intervention training for police will begin this month, among other changes to bolster behavioral health response and collaboration. But they must do the hard work of investigating promptly, and making the changes necessary to avoid another fatal encounter.