FOREST PARK, Ill, Sept 4, (AP): A man suspected of killing four people aboard a Chicago-area transit train shot them at close range while they were asleep, officials said Tuesday. The shooting took place before 5:30 a.m. Monday aboard the Chicago area’s L system, on a Blue Line train that was moving near where the line ends in Forest Park, a suburb about 10 miles (16 kilometers) west of downtown Chicago. Rhanni S. Davis, 30, was later arrested on another Chicago Transit Authority L line, according to police.

Authorities charged Davis with four counts of first-degree murder Tuesday. Forest Park Mayor Rory Hoskins said the victims likely didn't even see the shooter. "They were shot execution-style as they slept," Hoskins told The Associated Press. Margaret Miller, 64, and three men including Simeon Bihesi, 28, and Adrian Collins, 60, were fatally shot, according to the Cook County medical examiner's office. All of their addresses were listed as unknown. Police said they were still working to notify relatives of the fourth person killed, so his name has not yet been released.

Preliminary investigation shows the victims were on two different cars as the Blue Line train was headed toward Forest Park, police said. The Blue Line runs 24 hours and stretches from that suburb through downtown Chicago to O’Hare International Airport. It runs both below and above ground. The suspected shooter fled. But police found and arrested Davis thanks to video footage from the train, Hoskins said. Public records did not have a listed phone number for Davis.

A message sent Tuesday to a listed email was not immediately returned. Forest Park police and the Cook County state's attorney's office did not immediately respond to messages about Davis' legal representation. The Cook County public defender's office said it wasn't representing him. Davis is scheduled to appear in court at noon on Wednesday, according to Cook County State’s Attorney Kim Foxx, who spoke Tuesday evening during a media briefing in Forest Park. She called the shootings a "horrific, heinous and inexplicable act of violence” and said more details would come out during the court hearing.