The City Council on Monday announced that a proposed contract for technology that uses microphones and sensors to determine the location of gunshots and quickly alerts police will be held for one week.

According to Mayor Victor Gordo, city staff will bring to the council more information on Shotspotter, a system that records loud, impulsive sounds and alerts police in 60 seconds or less about the location of the gunshot. Advocates believe the system could save lives, deter shootings, and prevent the need to investigate non-gunfire-related incidents, such as fireworks.

The Pasadena Police Department has responded to more than 300 calls for service from people reporting hearing shots being fired, and an additional 400 incidents of gun-related crimes over the past two years.

In fact, less than an hour after the City Council announced the item would not be discussed, shots rang out in Northwest Pasadena.

In the past two years, nearly 40 people have been either killed or injured as a result of gun violence.

Close to 700 firearms have been seized by police.

Pasadena police Lt. Bill Grisafe said that after analyzing police data, ShotSpotter proposed to cover about a three-square-mile area of Pasadena that is most impacted by gun-related violence.

There was no mention of the specific area being considered.

According to a report to the council’s Public Safety Committee, which passed the matter last week, the Pasadena police intend to deploy ShotSpotter sensors in areas its own analysis shows are “most impacted by gun-related crimes.”

The ACLU claims that reasoning will increase the police footprint in Black and brown communities.

During the Public Safety Committee meeting, Councilmember John Kennedy, a committee member, asked staff to provide more data regarding the artificial intelligence-powered system.

Kennedy cited reports and concerns about the system’s efficacy and the possibility that it might result in over-policing in areas where gunfire detectors will be deployed, which he noted are areas of Northwest Pasadena.

In correspondence to the council, the ACLU claimed the technology is harmful to overpoliced communities.

“We can expect the acquisition of this technology to harm the most vulnerable populations in this city who have been overpoliced, oversurveilled, and undervalued in recent years,” the letter states.

City Manager Steve Mermell called Shotspotter a tool that allows police to respond and hopefully aid investigations.

Mermell stressed his belief there is a need for the system amid the uptick in gun-related incidents in the city over the past two years.

“It would be located in a portion of our city where we have the most incidents of gun violence and the people that live in those areas of our community should not have to put up with gun violence, and so I feel that if this tool can help, it’s worth a try,” Mermell said.

Just days after being deployed in Detroit, the software led police to a home being used by a gang to assemble, test and sell ghost guns. Seventy-five bullet casings were found in the backyard where the guns were being tested. One of the gang members was wanted in a non-fatal stabbing.

Critics cite studies conducted in Chicago and St. Louis that claim that the technology has not abated crime.

According to an investigation by the Associated Press, the system can miss live gunfire right under its microphones, or misclassify the sounds of fireworks or cars backfiring as gunshots.