Rhanni Davis, 30, was charged with four counts of first-degree murder Forest Park Police Department Police in Forest Park, Ill., have identified the suspect who allegedly opened fire and killed four people on a Chicago commuter train early Labor Day morning, Sept. 2. Three of the four victims have also been identified. In a press release shared with PEOPLE on Tuesday, Sept. 3, the Forest Park Police Department announced that 30-year-old Rhanni S. Davis of Chicago has been charged with four counts of first-degree murder. Davis is expected to appear in court on Wednesday, Sept. 4. The Cook County Medical Examiner's office also confirmed the identity of three of the fatal victims, per NBC Chicago, ABC 7, and WGN-TV. Simeon Bihesi, 28, was shot multiple times, and Adrian Collins, 60, and Margaret A. Miller, 60, were shot in the head. The fourth victim, a male, has not been publicly identified. However, the medical examiner's office noted that he died of multiple gunshot wounds, NBC Chicago reports. Related: 5 Shot After Gunman Opens Fire at Caribbean Carnival Parade in New York, Police Say 'This Was Not Random' PEOPLE reached out to the Cook County Medical Examiner's Office for comment. Police were alerted to gunshots fired on a Blue Line train around 5:30 a.m. local time on Monday, according to a police press release shared by the Village of Forest Park's official Facebook page. When officers arrived, the gunman had escaped. However, a suspect who matched the shooter's description was later captured on a Pink Line train in Chicago after authorities reviewed CTA Security surveillance footage. The Chicago Transit Authority (CTA) said in a statement to PEOPLE on Monday that it was an "isolated incident," adding, "This heinous and egregious act of violence should never have occurred, none the less on a public transit train." Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.           Forest Park Deputy Police Chief Chris Chin and Mayor Rory Hoskins, said the victims were sleeping when they were shot. "These victims, likely, never saw it coming," Hoskins told ABC 7. "They were executed on Labor Day. In our community, people go to the pool. They go to the park. You know, they barbecue. But, today, a lot of people were calling the mayor's office, expressing concern and asking if they were safe." NBC Chicago added that the four victims were not sitting together. Related: National Title-Winning College Gymnast, 21, Is Shot Dead in Wisconsin, 23-Year-Old Man Is Arrested Many commuters have since called for more security on the train. "I don't feel too unsafe," Ramis Wells told ABC 7, adding, "I would say there needs to be action taken, a little bit more security measures taken." Commuter Javari Dockery echoed a similar sentiment, stating, "We need more security. And people on the train because there don't be nobody on the train, so you're just on there with random people and anything can happen." Mike Ganter, who is also a commuter, pointed out the heavy security presence on site Tuesday morning. "That's public transportation," he told the local news station. "Somebody going to be on there. There's no way to stop or prevent that." For more People news, make sure to sign up for our newsletter! Read the original article on People. (People.com Latest News) More