And ABC7 talked to his childhood friends, who say they often spent time at Valley Forge Park over the years. They said it is shocking to hear that McGann is facing capital murder charges in connection with a double fatal stabbing.
McGann, 28, was taken into custody earlier this week after he allegedly attacked Clinton and Cristen Brink while the couple was hiking with their two young daughters at Devil's Den State Park.
Police say the mother rushed her daughters, 7 and 9, to safety during the attack before returning to her husband and was attacked, too. Investigators say the assault appeared to be completely random.
It is a tragedy that has hit home for many in Chicago, as one man, Bill Englehart, says he grew up with McGann near Midway.
"He was seemingly normal. Just played sports, was a nice kid. I couldn't even imagine this would happen," Englehart said.
Special agents arrested McGann at a barbershop this week in Arkansas as he was getting a haircut.
Englehart says he and his friends often hung out at McGann's home in Garfield Ridge and they all played on the same sports teams.
He says it is hard to fathom the fact that the guy he was once friends with could be accused of this crime.
"Normal family, you know. His brother was cool. It's a shock. I just want to send my condolences to the family and all the families affected in Arkansas. Everything, it's just brutal," Englehart said.
Englehart says he has not spoken to McGann in more than 10 years, but he wonders where things may have changed mentally for the suspect.
He says McGann moved to Oklahoma, at some point, after graduating from Fenwick High School in Oak Park in 2015.
Investigators say McGann was a teacher in Oklahoma during the 2023 school year but was placed on administrative leave that year for what the district says was related to classroom management, professional judgement, and student favoritism.
The district says an internal investigation found no evidence of inappropriate behavior, but McGann ultimately resigned.
He was recently hired to teach at a school in Arkansas this upcoming school year before he was arrested in connection with the killings.
"The first thing you think of is, 'How can someone possibly do this?' And then, a second thought makes you think, 'What went wrong? Something had to have gone wrong,'" Englehart said.
McGann allegedly left behind blood and DNA, and prosecutors say there is no connection between the suspect and the victims.
McGann made his first court appearance on Friday morning. He was held without bond.
Investigators say McGann has been cooperative with them, but a motive is still unclear.