Dan Popp entered the courtroom to find out his fate in front of a packed house here to support those he killed.
"I'll never forget the sound of the gunshot that rang through my ears from the bathroom as my dad was being executed," said Isabelle Vue.
Vue's parents Phia and Mai Vue were both shot and killed by Popp in their apartment complex on 92nd and Beloit back in March of 2016. Popp then murdered Jesus Manso-Perez and tried to kill Manso-Perez's son.
"Mr. Popp is laboring under delusional beliefs at this point that the world is ending," Popp's defense attorney stated.
Popp's sister Dawn Johnson said it's clear he suffered from mental illness.
"I know in the deepest part of my soul my brother never meant for this to happen," Johnson said.
Last month, the jury decided Popp suffered from mental disease, but that he could appreciate the wrongfulness of his conduct.
"I don't think anyone the fact that Mr. Popp had a mental disease," said Judge Jeffrey Cohen.
When it came down to sentencing, Cohen says he was stuck with the jury's decision. The victims' families said they left court relieved Popp will spend the rest of his life in jail.
"We can't bring Pia and Mai back, and Dan Popp will be in jail for the rest of his life but he still has his family," said family spokeswoman Maizong Vue.