Chicago man charged with murder in the deaths of 4 people sleeping on a train

An Illinois man was charged Tuesday with murder in connection with the Labor Day shooting of four people who authorities said were sleeping in their seats on a Chicago-area commuter train.

The Cook County State’s Attorney’s Office charged Rhanni S. Davis, 30, of Chicago, with four counts of first-degree murder, according to the Forest Park Police Department.

It was not immediately clear Tuesday afternoon whether Davis had secured an attorney. The Law Office of the Cook County Public Defender did not immediately respond to a request for comment.

In a statement, the county medical examiner identified three of the victims: Adrian Collins, 60, who suffered a gunshot wound to his head; Margaret A. Miller, 64, who also suffered a gunshot wound to her head; and Simeon Bihesi, 28, who suffered multiple gunshot wounds.

The fourth victim, who was also shot multiple times, remained unidentified, according to the statement.

All appeared to have been sleeping when they were shot and were seated apart from one another in two different train cars, police said after reviewing security footage. Three victims died immediately and the fourth at a hospital, authorities said.

Forest Park Police Department Lt. Daniel Pater said at a news conference Tuesday that ballistic evidence recovered from a gun the suspect was allegedly carrying when he was taken into custody matched evidence found on the train.

He said six rounds were fired from a 9mm handgun, including five on one car and one on another. Police have recovered all the casings, Pater said.

Kimberly Foxx, Cook County State’s Attorney, said at Tuesday's news conference that the alleged the shooter stood over the victims and "pumped bullets into their body."

"I think it is safe to say that this was a random attack," she said.

Forest Park Deputy Chief Chris Chin said during a news briefing on Monday that a suspect had been taken into custody and a weapon recovered.

“This appears to be an isolated incident on this unfortunate day,” Chin said. “It’s a horrible situation.”

The shooting occurred around 5:30 a.m. on a moving Chicago Transit Authority train at a Blue Line station in Forest Park, authorities said on Facebook.

The suspect was found on a Pink Line train line, police said, adding they were also trying to track down a person they believed witnessed the attack.

Chin credited Chicago police with finding the suspect after a description had been broadcast to area authorities. He also praised Chicago Transit Authority security for their help with the ongoing investigation.

The Chicago Transit Authority called the shooting a “heinous and egregious act of violence” that never should have happened on a public train.

The Chicago Coalition to End Homelessness said in a statement that violence against homeless people is not random and that more needs to be done to protect them from crime.

"Everyone has the right to feel and be safe in our community, regardless of their housing status," it said.

At Tuesday's news conference, Chicago Transit Authority President Dorval R. Carter said he was unable to say whether the victims were homeless.

“Clearly, in this particular case, there were individuals sleeping on the train,” he said.

Pater, who's leading the probe, said security video from the train has been crucial to the case so far. "Surveillance video was key," he said.

The suspect was due in court Wednesday afternoon. While authorities seemed confident in their case and the evidence they've collected, a motive remained unclear.

"It is horrific," prosecutor Foxx said. "We want answers."

This article was originally published on NBCNews.com