On Chicago PD Season 5 Episode 2, Chicago PD officer Frank Toma becomes a suspect after a bombing at a street fest during his shift.
When the CPD can't locate Toma, a former trainee of Detective Kim Burgess, she takes it upon herself to find him.
A routine visit to his house finds Jihad websites on his browser and further intel reveals he'd been frequenting a radical mosque under an alias and conspiring with the men involved in the bombing.
All evidence points to him being a homegrown sympathizer but Burgess is hesitant to believe it.
Still, since no one is claiming responsibility for the attack, it means that there's going to be the second one.
Intelligence is racing against to clock to find the bombers before they injure and kill more innocent souls.
After a few leads and more incriminating evidence against Toma, Denny tells the media "one of their own" was an ISIS sympathizer.
Pretty soon, Toma's face is plastered all over the news.
Except Burgess still refused to believe that he's a "terrorist."
Eventually, Intelligence gets a hit on Toma's car and she finds him zoned out, holding a gun to his chin.
He's rambling on about how he was trying to help and no one will believe the truth.
As she tries to talk him down, he pulls the trigger.
Before he does, he tells her about a letter in his bag that "explains everything."
After Voight benches her because she's too close to the case, she teams up with Antonio and follows the letter to an address.
To the naked eye it looks like Toma was actually radicalized, but after she digs up his journal it becomes apparent that he was running an undercover operation to stop them.
The journal helps Voight & team narrow down the second bomb and they stop the bombers just in time.
Burgess follows through on her promise to Toma, breaking the news of his death to his parents.
Unfortunately, Voight is unable to clear his name.