Florin Mulosmani, 24, faces one count of first-degree murder for the attack that happened about 5:15 a.m. May 28 in the 6300 block of West Montrose, according to Chicago Police.
Mulosmani and another man got into a fight at a gas station with the 23-year-old Cionzynski, who was shot in the head and pronounced dead at the scene, according to police and the Cook County medical examiner’s office.
Police did not say if they thought Mulosmani pulled the trigger.
Cionzynski lived in the 4400 block of North Nashville Avenue in northwest suburban Harwood Heights. Mulosmani is from the 1900 block of South Grove Street, police said.
A judge ordered him held without bond at a Saturday hearing, according to the Cook County sheriff’s office. He is due back in court Monday.
Cionzynski was among six people killed and 63 wounded in shootings over the holiday weekend.
—Chicago Sun-Times Wire