Edward Brown has been charged with aggravated unlawful use of a weapon and reckless discharge of a firearm, the Cook County State's Attorney's Office said. Investigators believe officers Conrad Gary and Edward Marmolejo were investigating reports of those shots fired on Metra tracks when they were struck and killed by a South Shore Line train.
Brown is due in court for a bond hearing Thursday at 1:30 p.m.
Chicago police investigators have also acquired the event recorder - the black box that was on board South Shore train 119.
"It shows the time, it shows the speed of the train, it will show when the train was braking," South Shore Line President Michael Noland explained.
Based on the body cam footage from one of the officers, police believe the sight and sound of an approaching northbound train masked the sound of another southbound train as the officers searched the Metra tracks.
"It will show when the train sounded the horn and for how long," Noland said.
Funeral arrangements the officers were finalized Wednesday, Chicago police said.
The wake for Officer Gary will take place on Thursday from 3-9 p.m. at Blake Lamb Funeral Home (4727 W. 103rd St., Oak Lawn) and the funeral will take place at 9:30 a.m. Friday at St. Rita of Cascia Shrine Chapel (7740 S. Western Ave., Chicago) with a private internment.
The wake for Officer Marmolejo will take place on Friday from 3-9 p.m. at Blake Lamb with a funeral at St. Rita at 11 a.m. Saturday with a private internment.
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The officers were struck and killed by a commuter train in the Rosemoor neighborhood on the South Side.
Gary, who had served on the force for 18 months, is survived by his wife and infant daughter. Marmolejo, who served on the force for two and a half years, is survived by his wife and three young daughters.
Wednesday afternoon, the Chicago Police Memorial Foundation delivered $60,000 checks to the families of both officers. Verified GoFundMe pages for both officers have collected in total more than $78,000 for their families.
Meanwhile residents in the Pullman neighborhood have been wrapping trees with bright blue ribbons.
"It's our way of telling the police officers here in the 5th District we feel your pain and we support you in this time of need," said neighbor Tim McMahon.
VIDEO: Mayor Emanuel speaks at 5th District after officers killed by train
Mayor Emanuel said he was able to sit down with Marmolejo's wife and family and offer condolences.
"I think the Chicago police family, more than ever, needs the Chicago family," Emanuel said. "We all have to lean in on them and give them a shoulder to lean on."
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Outside the 5th District Police Station where they were based, blue ribbons are tied to the trees outside in memory of the officers and some have even left flowers in front of the building as officers struggle to cope with this tragedy.