2023 Chicago Halloween party shooting

On October 29, 2023, at around 1:05 a.m., a mass shooting occurred at a business hosting a Halloween party, wounding fifteen people. Police alleged that the shooter was a partygoer that was thrown out of the venue, who later returned with a handgun and fired into a crowd of people. The shooter fled the scene on foot before being arrested by police a short distance away. The party was an unlicensed event attended by over 100 people, and the venue, Studio 1258, has a litany of accusations of dubious activity, with the city receiving hundreds of complaints in the months before the shooting.

Shooting
According to police, the alleged gunman was ejected from the party following a "disturbance". The manager of the venue stated that the suspect was involved in several incidents, including bumping into people and knocking their drinks over, while being visibly intoxicated, which led to his removal by security. He attempted to return to the party, but was blocked from doing so by a security guard, and became involved in a physical altercation outside the venue before leaving again. Later, at around 1:05 a.m., as the party was ending, the gunman returned once more and opened fire "indiscriminately" into a crowd of people inside the venue with a .357 caliber Sig Sauer semi-automatic handgun. One witness stated that the shooter "put his arm through the door and started shooting".

Witnesses describe hearing the glass inner door leading to the party being shattered as gunfire rang out. Attendees ducked for cover or got down on the ground to evade gunfire. A security guard was heard yelling for people to "get back" shortly before the shooting began. Several witnesses recount seeing people fall to the ground as they tried to run away from the shooter. A video of the scene uploaded to social media appeared to show victims bleeding on the ground. A total of 17 shell casings were recovered from the scene.

Police responded to the scene as the shooting was ongoing, however the shooter fled on foot. After being pursued by a venue security guard and police, a suspect was arrested a short distance away from the scene with a handgun in his possession.

The party where the shooting took place was arranged by two comedians, who advertised the event on social media. The alleged gunman bought tickets to the event and had taken a selfie with a performer prior to his removal from the party. A lawsuit filed in February 2024 alleged that the venue did not have a licence to sell alcohol or host such parties and lacked basic safety measures.

Legal proceedings
The suspect was identified as 48-year-old convicted felon William Groves, who was charged with 32 felony counts, including 15 counts of attempted murder, 15 counts of aggravated battery, one count of unlawful use of a weapon by a felon and one count of firing in an occupied building. Groves pled not guilty to the charges.