The troubled son accused of killing his retired detective dad inside their Long Island home chillingly confessed to the grisly slaying — telling cops he blasted his father in the head to “finish him off,” prosecutors revealed Thursday.
Christopher Miller, 43, pleaded not guilty for reasons of insanity in a Suffolk County courtroom Thursday for allegedly fatally shooting his dad, retired Suffolk County Police Department detective John Miller, 75, during an argument inside their home Wednesday morning.
When police questioned the younger Miller, he said “he shot his father four times with a shotgun before driving the pointed end of the weapon into his head to finish him off,” according to a criminal complaint.
The deadly clash unfolded inside the Dix Hills home hours after John Miller reported his son missing.
Christopher Miller was hospitalized Monday after fighting with a motorist during a crash and his father grew worried when he didn’t hear from him, leading him to file a missing person report, News 12 reported.
The dad picked him up at the hospital Tuesday — and the accused psycho son laid out a shotgun and AR-15 on his bed before opening fire hours later, prosecutors said in court, according to the station.
After the killing, Miller ran from the home and hid in a neighbor’s shed.
The eagle-eyed homeowner spotted him and called police.
Cops then brought him to his home, where they discovered the former detective in a pool of blood.
The 43-year-old — who recently moved into his father’s home after going through a divorce — tried to run but was tackled by a cop, the outlet said.
A bruised-up Miller ignored reporters as he was led to his arraignment Thursday morning.
He pleaded not guilty to murder charges and told Judge Eric Sachs he wanted a different lawyer, according to News12.
Miller was held without bail.
His appointed lawyer Dan Russo told reporters “he’s going through something traumatic” outside the courthouse.
“I don’t know if it’s psychiatric or some other health concern, but he’s definitely going through something.”
Police did not provide a motive for the patricide.
The doomed dad — who worked 24 years with the Suffolk County Police Department and retired in 1995 — was also a former chief at the Wyandanch Volunteer Fire Company.
“Ex-Chief Miller was a decorated Suffolk County Police Department Detective and an avid volunteer, with a dedication to service few men could replicate,” the West Babylon Volunteer Fire Department wrote on Facebook.
“His resume, knowledge, and demeanor allowed him to become a role model for many first responders throughout the Town of Babylon.”
A former firefighter colleague teared up outside the victim’s home on Thursday.
“He was a great, great guy,” Tom Arcese told News12 while wiping away tears.
“All around great guy. [He] pulled us all together and really got it going at the firehouse, where he mentored a lot of people. He meant a lot to this community for a long time.”
Miller’s grieving family declined to comment when reached by The Post Wednesday night.
Additional reporting by Brigitte Stelzer