His grandparents have been critical of the investigation. They could not be reached about the report Wednesday.

The review says the officer “fired his personal weapon in the proper exercise of self-defense, defense of others, and under the protection of the Castle Doctrine.” That refers to Missouri’s self-defense law, passed in 2007, that protects homeowners from being charged or being found liable for damages if they harm invaders.

“The evidence clearly establishes that (the officer) was justified in using deadly force to protect himself and his family against the unlawful entry made by Gebhard into the residence,” McCulloch’s report concludes.

His stepfather told police Gebhard’s behavior at times “had spiraled out of control,” the report says. Gebhard’s family last had contact with him July 8, when he told a stepsister that “this is the last time you’re ever going to see me. I’m headed to Dallas to start killing cops.” (Five Dallas police officers had been slain by a sniper the day before.)

His family tried to contact him the next day but failed and reported his vehicle missing to police.

McCulloch’s report says that a toxicologist concluded Gebhard’s “perception and judgment were impaired” because of the level of marijuana in his system.

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