(KSDK) - Police say the death of one of their own after a fire in North St. Louis County was the result of a homicide.
51-year-old Dierdre Exum was found inside dead inside her home on Chesapeake Drive in Spanish Lake. Exum was an armed security officer with the St. Louis County Police department.
Investigators have determined the cause of death was blunt force trauma.
Bomb and arson crews worked late into the night Friday trying to figure out what caused the fire, and Exum's death.
A neighbor spotted the flames Friday. Firefighters forced their way in and found Exum on the floor.
"It hurt," says a neighbor. "I hoped she wasn't in there. But that wasn't the way it turned out."
The neighbor did not want to be identified because of the possibility that someone did this on purpose, and could still be out there.
"You never know. But i'm not worried because I don't know somebody that would do something like that."
Still she was cautious when talking about the woman she'd known for five years. She says Exum was a friendly neighbor.
"She cared about the neighborhood. She was the neighborhood watch. She would walk around at night time, which I don't think I would have done. And she had this big dog with her...a Rottweiler and he was friendly with me.
Exum leaves behind a son, and an entire St. Louis County police family mourning her loss and working to find out why she's gone.