The Chicago Police Department is expanding the use of a gunshot detection system and surveillance cameras in areas of the city that are dealing with high rates of gun violence.

Police Superintendent Eddie Johnson said in a statement the expanded ShotSpotter system and crime cameras will be in police districts on the South and West sides. Police say the 13.5-square-mile area is where the majority of gun-related violence is taking place.

Johnson said the technology “allows us to police smarter and be more proactive than reactive when it comes to responding to and investigating shooting incidents across the districts.”

The ShotSpotter system, which includes sensors and is used in other cities, was launched in Chicago in 2012 in two 1.5-square-mile areas of the same police districts.