CHICAGO (CBS) — Three people were shot – two fatally – a domestic-related attack in south suburban Posen on Friday afternoon.

It appears to have started with an angry ex-boyfriend. Relatives of the victim say he attacked her and killed her current boyfriend.

Law enforcement sources say Blue Island police then killed the ex-boyfriend, who was hiding in a garage down the street.

Officers armed with automatic weapons looked through alleys and yards, not sure how many gunmen were on the loose.

A distraught relative of a victim tried to get information about her cousin- Jenna Sammon. Another relative says Sammon had been attacked by her ex-boyfriend earlier in the day.

“When she went to the basement to do her laundry, he popped up out of nowhere and attacked her and started stabbing her with a screwdriver,” Derrick Toombs tells CBS 2’s Roseanne Tellez.

Toombs says when Sammon returned to her home from the hospital and sent her current boyfriend in first while talking to her cousin on the phone. That’s when the shooting started.

“She said, ‘Oh, my God I’m shot,’” he says.

She tried to flee, but a block later, the car, with several visible bullet holes, came to a stop.

Residents watched all the  police activity in shock.

“I saw them take a man in handcuffs from the house down the street. This is absolutely shocking. You know what? I grew up here and this is not our town,” Joe Biesiada said.

Posen police have been very tight-lipped, confirming only a domestic homicide and a police-involved shooting. They continue to investigate along with the Major Crime Task Force and the State Police Public Integrity Task Force.

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