CHICAGO — A man has been charged in the weekend shooting that injured 15 people, Chicago police announced Tuesday.

William Groves, 48, has been charged with 15 counts of attempted first degree murder, 15 felony counts of aggravated battery with discharge of a firearm, one felony count of unlawful use of a weapon by a felon and one felony count of aggravated discharge of a firearm in an occupied building.  

Groves is expected to have his first court appearance Tuesday at noon.  

According to police, the shooting happened just after 1 a.m. Sunday in the 1200 block of South Pulaski Road at Studio 1258.

Officers say around 100 people were gathered inside the building. Officials Tuesday said Groves was in an altercation inside of the establishment, not allowed to return and then allegedly opened fire into the crowd. 

According to police, two people, a 48-year-old man and a 26-year-old woman were both critically injured in the shooting and 13 others, ages 26 to 53, were reportedly in good condition when taken to the hospital. At Tuesday’s news conference, police said all of the people who were injured have upgraded conditions. Police said all now have non-life-threatening injuries.

Several of Groves’ family members attended Tuesday’s court hearing, including some of his adult children. They all declined to comment.

Police say Studio 1258 had been operating events without a license. The day after the shooting, CPD issued a Summary Closure which determined that the establishment presented a danger to the public.

Mayor Brandon Johnson and Cook County State’s Attorney Kim Foxx joined police for a news conference announcing the charges. Officials thanked the swift actions of partygoers who helped police identify Groves who police say was in possession of a .357 caliber handgun.  

Police have teamed up with a North Lawndale nonprofit to bring a critical resource to the community to help those impacted by the tragedy.

The Crime Victim Assistance Program is set to take place on Tuesday.

With the help of YMEN and other local organizations, CPD will offer one day of crisis counseling, financial loss guidance, access to therapy dogs and additional social services.