On Wednesday, the majority of City Council members approved an order, giving themselves control over the technology and allowing more time to collect data on how it works.
But Mayor Johnson claims the measure isn't legal, and he still plans to get rid of ShotSpotter in the fall.
Future of ShotSpotter uncertain after Johnson called city council's vote 'illegal'
Chicago police have been using ShotSpotter for several years. It became controversial after some studies questioned its effectiveness, and when Johnson promised to get rid of it.
"I canceled ShotSpotter; it's canceled," Johnson said Wednesday.
Technically, the mayor has no power to cancel a contract: Contracts expire.
Johnson extended the contract until the fall.
In an effort to save it and curb the mayor's power, 34 City Council members, including some of the mayor's allies, voted for a measure that orders the police department to collect more data and then let City Council decide to keep ShotSpotter or not.
"My authority is quite clear. This passage on whatever it was has no bearing on my executive authority," Johnson said.
While the mayor claims the measure is not legal, the order's sponsor, 17th Ward Ald. David Moore, argues it is.
"It's legal because, as aldermen, we have contracting authority, and we have budgeting authority. So, we can present any ordinance that says we want to contract with ABC," Moore said.
Moore's argument is backed up by municipal code legal expert Burt Odelson. ShotSpotter supporters consulted Odelson before the order was crafted.
He said, as the legislative branch, City Council's role is to pass legislation and appropriate money.
"The mayor has to stay in his lane, and the City Council has to stay in their lane, and neither one should be transforming themselves is assuming the power of the executive or of the legislative branch," Odelson said.
After inquiring Thursday why the measure is not considered legal, The mayor's office did not have an explanation.
Mayor Johnson has the option to veto the measure.
Thirty four votes are needed for an override, the same amount it took to pass the order Wednesday. But, that does not mean there will be 34 votes once data is collected and the Council votes on the ShotSpotter contract.