A Colorado murder suspect says he shot a woman because he was convinced she was his dad and underwent gender reassignment surgery, according to police.

Joseph Saur, 19, was arrested on first-degree murder charges in connection to the death of 28-year-old Patricia Stewart, the Montrose Press reported.

Police said that Saur entered the camper Stewart was sleeping inside and shot her multiple times in the face Sunday night in Olathe.

He then headed to the police department and confessed to police that he had shot his father.

Authorities said the distraught teen was “clearly under the influence of some kind of drug.”

Saur told investigators that his “real biological father” had a sex change to “keep from being caught.”

“Joseph stated he acted in self-defense by shooting his father, [who] he explained had done bad things,” according to the police report obtained by the Montrose Press.

Saur’s dad, who was found alive and well, told police that he was concerned about his son’s alleged meth use. The teen, however, denied using drugs to police.

Authorities, eventually, were able to determine the location of the crime from Saur’s description.

Stewart’s body was discovered with wounds to her face in the upper bunk of the camper. Her death was ruled a homicide.

Saur is being held without bond at Montrose County Jail, news station KUSA reported.