DOUGLAS COUNTY, Colo. — The deaths of a Highlands Ranch mother and her two young sons last month has officially been ruled a murder-suicide, the Douglas County Coroner’s Office said Friday.

The coroner’s office determined that 38-year-old Jennifer Laber died of a self-inflicted gunshot wound, and that 3-year-old Adam and 5-year-old Ethan both were shot in the neck.

The three were found dead in a minivan parked in the loading dock area of a closed Sports Authority store in Lone Tree on Nov. 30.

The autopsy also revealed that the boys were heavily drugged before their mother killed them. Both of the boys had evidence of oxycodone, oxymorphone and diphenhydramine in their systems.

Their father, Ryan Laber, hinted at this in a public Facebook post on Thursday talking about his wife’s depression. He said his sons were in a “deep sleep” when they were killed.

“It’s first critical to know Jennifer Krannich Laber had a deep depressed episode,” Laber wrote. “We don’t know what triggered it, nor did any of those close to her see it coming. From her history, previous episodes involved very low self-esteem, no recognition of consequences to self harm, and a strong desire to escape.”

Laber also added that his wife left a note saying that despite having lost 80 pounds she felt self-conscious.

He added: “Depression is a sickness. It is coercive and often operates in silence. There is no fault to lay blame.”

Laber added that Jennifer was a “tremendous mom” and she felt her emotional distress could only be resolved in heaven so “as an act to insure she could provide the best motherhood to her boys, she took them with, painlessly, while they were under a deep sleep.”