Estep's wife paid the required 10 percent, $20,000, on Tuesday evening, at around 6:40 p.m. on Tuesday, according to the Tribune. Estep's attorney had earlier indicated in court that Estep could post only about $5,000.
Estep was also charged with a misdemeanor count of trespassing without paying at a CTA stop, but police say no additional details are available at this time.
On Aug. 1, the 46-year-old casualty, Ben Benedict, was holding up to board a prepare at the Washington station when another man moved toward him from behind.
Estep is being held on $200,000 bail, DNAInfo reports.
Benedict said Estep was standing just feet away from him on the platform for "two or three minutes" minutes prior to the unprovoked attack. Benedict, perplexed a prepare could arrive, shouted for offer assistance.
Police did not issue an alert after the attack.
A video released by police more than a month after the alleged attack - following an inquiry by the Tribune - showed a suspect hopping a turnstile at the station, but didn't show footage of the incident.
"There's no information that they knew each other prior", Chicago police spokesman Anthony Guglielmi told the newspaper. But after Benedict spoke to the Chicago Tribune about the attack on September 7, police released more information.
Estep is now working as a senior data analyst at healthcare company Procured Health, according to his LinkedIn page.
His attorney, Vadim Glozman, disputed prosecutors' version of events, saying that the identification of Estep was tenuous because the surveillance images were unclear. Only after other commuters were able to circle the attacker was Benedict able to safely get back to the platform, Benedict told the paper.
He looked down the tracks but didn't see a train approaching. Benedict fell on the tracks, missing the zapped and conceivably destructive third rail, and after that gazed toward the man who'd pushed him.
"It was like a lion looking at his prey, that's kinda what it looked like to me", he said.
The man pushed the casualty, making him fall onto the tracks.
Benedict told the Tribune the attack wasn't an accidental nudge, but a "full-on running push".