“Pick a crisis: guns, gangs, prisons we can’t afford, health-care bills we can’t pay … yet

60 percent of the money made by Mexican drug cartels is coming from marijuana,” he said. “All you have to do is join a gang, get a gun, (because) we’ve put a pot of gold next to the thing we said people can’t have: drugs.”

The criminalization of pot has been especially good for gangs, he said, because that is where they make their money.

“All you need to go into the drug business is a pair of tennis shoes and a gun,” he said. “We corrupt the police just like we do the kids because of temptation.”

Illegal drugs not only put police in danger via enforcement attempts, Gierach said, but put officers in a position to make criminal decisions, too. Drug money that is confiscated in busts often cannot be precisely accounted for, he said, and thousands of dollars in drug money often are left in the hands of a cop’s conscience.

And then there are the jails.

“We have 2.3 million people in prison — the highest rate of incarceration in the world,” he said Friday. “In Cook County, more than half the inmates are nonviolent (no gun was used in the crime) drug offenders.