Chicago Police touted a drop in September gun violence at a press conference Sunday morning, even as the weekend saw at least 33 people shot in the city, four fatally.

September was the seventh straight month that saw a reduction in gun violence in 2017, First Deputy Supt. Kevin Navarro said at the press conference at CPD headquarters.

This September saw 57 deaths that were ruled homicides, with 488 shooting deaths this year ruled homicides, according to data kept by the Chicago Sun-Times. That total accounts for a 2.6 percent drop from last year’s 501 shooting homicides through September.

In all, the city has recorded at least 524 homicides so far in 2017, including shootings, assaults and other types of incidents, Sun-Times data shows. Chicago suffered one of its bloodiest years in two decades in 2016, with more than 4,300 gunshot victims and nearly 800 total homicides.

In 2017, however, Chicago seen has a 7 percent reduction in murders and a 16 percent reduction in shootings, Navarro said.

In an effort to continue the reduction of shootings this year in Chicago, police also announced plans to double the amount of police districts with ShotSpotter gunshot detectors, police said.

Twelve of the city’s most violent districts will now be outfitted with the sensors, as well as new “nerve centers” that will allow officer and civilian analysts to comb through crime data and use predictive analytics, police said.

“It has helped us to completely change the way we police in Chicago,” Navarro said, noting that every district equipped with the centers has seen a reduction in shooting incidents this year, including the 7th (Englewood) District, which has seen a 40 percent drop in shootings from last year.

So far this weekend in Chicago, four people have been killed and at least 28 others wounded in shootings.