Ex's Dad Says Man Told Him: ‘I'm Sorry; I Killed Them'

A North County man who came home from work to find his wife and daughter covered in blood testified in the case against a former son-in-law he now only refers to as "the defendant."

Jason Cooper of Fallbrook faces two counts of murder for stabbing his mother-in-law Robyn Liebner and his 16-year old sister-in-law Jenna Liebner multiple times, according to prosecutors.

The murder scene was described as “extremely brutal” by investigators when it happened April 26, 2006.

Tom Liebner stumbled on the murder scene inside the family’s Fallbrook home when he came home from work. The victims’ husband and father testified in court Monday in the case against his once son-in-law.

“He said, ‘I killed them. I killed them. I’m sorry, I killed them,” Liebner testified Monday according to our media partner the North County Times.

Liebner told the courtroom he found the suspect kneeling on the floor of the family room rocking back and forth. He noticed Cooper had two knives and a cordless phone next to him. When he picked up the phone, he realized Cooper had already called 911.

"I asked the defendant why he did it," Liebner testified. "His response was 'Jenna said something that made me angry and I lost it.' I said, 'Where are they?' He pointed toward the foyer."

Cooper, 27, has pleaded not guilty by reason of insanity. He suffered brain damage following a fall while he was in the Army, according to his attorney, and was subsequently given a medical discharge from the service.

Investigators said the killing involved money. The defense said the argument was sparked over something minor, a medieval book.

Liebner’s daughter Amber, Cooper's ex-wife, will testify Tuesday.

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