COLORADO SPRINGS, Colo. — A 19-year-old suspect who is accused of stabbing his younger siblings in Colorado Springs on Tuesday had talked about killing before, his father told police.

A police document revealed details from detectives’ interviews with the suspect, Malik Murphy, and his father, Jefferson Murphy.

Malik Murphy told police that he often had “homicidal ideations,” and planned to kill his family and bury them in the backyard so he could be alone at the home.

RELATED: Malik Murphy police affidavit 

He told police he purchased the knife at a Walmart in Colorado Springs several months ago, the affidavit says.

Jefferson Murphy told police that he woke up to one of his children screaming in the basement. He went to check and was confronted by Malik Murphy.

Malik Murphy then stabbed his father with a knife and they fought until Jefferson Murphy was able to detain him in the garage, according to the police document.

Malik Murphy slept in the same room as his younger siblings. He told police he stabbed both of his siblings three times.