The fallout of Wednesday's vote and the promised veto could extend into the upcoming budget negotiations.
Aldermen voted 33-14, falling one vote short of a veto-proof majority.
On Sunday at midnight, the ShotSpotter system around Chicago will go dark and there will be no more alerts sent to Chicago police. That has some aldermen worried.
"Let's see what happens this weekend, Monday, when the mayor's first homicide happens and there's no technology to help offer aid to that person," said 15th Ward Ald. Ray Lopez.
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Mayor Johnson said money that will be saved by ending ShotSpotter will be reinvested in other technology that is part of a holistic approach to public safety.
"We're open to technology, but it has to be technology that works. So it's not just simply about redirecting it. It's about making sure that the people of Chicago are getting what they're what they deserve," he said.
The mayor's claims of being a collaborator are now under question after he promised to veto an ordinance that could extend ShotSpotter that was supported by 33 council members.
"I think he's been more of a dictator when it comes to, this is what I want. This is what we're going to do, and that's it," Lopez said.
"As we work to decommission this particular technology, we've had a working group to with stakeholders to think about other forms of technology, our administration has been incredibly collaborative," said Johnson.
The mayor said he's not afraid of the fallout from this issue potentially impacting upcoming budget negotiations. But he could be in for a rude awakening.
"This will have repercussions, whether he believes it or not," said Lopez.
Late Thursday afternoon Sound Thinking, the company that owns the ShotSpotter technology, said in a statement they will begin removing their technology on Monday while remaining hopeful that the contract could get extended.