When do “a few bad apples” finally become a worm-infested bushel? The 72 police removed from the streets by Police Commissioner Richard Ross last week for their racist and offensive social media posts is well more than a few. And the research project that originally discovered the social media posts found hundreds of offensive posts originating from Philadelphia.

Add to that the decades of instances of police corruption, brutality, and racism in Philadelphia — after which everyone assures themselves and us that a few bad apples shouldn’t taint the whole department.

We’ve seen enough bad apples now to say that we have a problem in policing.

Of course, the problem is not limited to Philadelphia. The Plain View project that uncovered social media posts from police departments in eight jurisdictions across the country found thousands of racist and offensive social media posts. Last week, as a result, a St. Louis prosecutor barred 22 officers from testifying in court.

This particular policing problem isn’t new, nor should it be surprising. The strains and conflicts within police departments reflect issues within the culture at large. But policing needs a radical change.

Whom do we look to for this radical change? Commissioner Ross took laudable action last week in taking cops off the street, but a police commissioner is, by definition, both a part and a product of a historically opaque system. The city’s police advisory commission doesn’t have the authority to demand real change; it’s refraining from responding to this development until the cases of the 72 are resolved. The Fraternal Order of Police typically defaults to defending its members no matter the circumstances. Other than praising Ross’ action, the mayor hasn’t issued much of a statement, either. So whom should citizens look to for answers – especially those citizens most vulnerable to the actions of cops so racist they can’t keep from broadcasting it?

This is a crisis. Where is the leadership?

Mayor Jim Kenney has the ultimate authority to chart a course for the necessary radical reform. He should make a forceful statement that includes a plan for what he’s going to do about it.

A recommendation: He should gather the best minds in the region to create a version of President Barack Obama’s task force on 21st-century policing. That particular project — cochaired by former Philadelphia Police Commissioner Charles Ramsey — gathered academics, law enforcement, and activists and in just six months studied and produced a set of recommendations for what we can and should expect from our police. Kenney should create a local version of this, involving some of our universities, law enforcement, and community members. Charge them with creating a blueprint that would involve research, data collection, and recommendations for what Philadelphia’s police force should look like – and act like – in the 21st century.

Mayor Kenney is smart enough to know that meaningful change can’t happen without outside scrutiny — to which the Police Department is rarely, if ever, subjected.

He’s also smart enough to realize that it would be better for the city to get in front of this now, instead of waiting for the courts to intervene.