Wilfredo Rivera is the only son who didn't live at his father's house in Winnetka. It was there that Edwin Rivera shot and killed his father, two brothers, and SWAT officer Randal Simmons.
Wilfredo says his brother was a hard worker and well-educated, but also troubled.
"I took him to the hospital, I wasn't sure for what, and as we spoke in the car on the way there he didn't really want to tell me what, he just wanted to speak to a doctor," said Wilfredo Rivera. "They worked so hard. This is all their work. I have to do something to keep it."
Wilfredo's father and brothers worked together at the family's trucking company.
He says the last time he saw his brother was at a Super Bowl party and nothing seemed out of the ordinary.