Federal prosecutors have explained why they don't think ex-Briarcliff Manor cop Nicholas Tartaglione was present when three men were fatally shot in an Orange County bar.

He was busy transporting the body of another victim to his ranch, the prosecutors contend.

That was among several new details on the deaths of Martin Luna, Urbano Santiago, Miguel Luna and Hector Gutierrez included last week in a letter to U.S. District Judge Kenneth Karas.

NOT THERE: Tartaglione not present when 3 victims shot

FOUND: 4 bodies discovered on land Tartaglione rented

BIGGS: Second suspect charged in quadruple homicide

Prosecutors urged the judge to deny a defense request for detailed evidence as to how authorities knew Tartaglione wasn't there when Santiago, Gutierrez and Miguel Luna were shot.

Authorities had previously revealed that the killings were a result of a drug deal gone bad between Martin Luna and a group that included Tartaglione.

According to Assistant U.S. Attorney Maurene Comey, Tartaglione suspected that Luna had stolen money that was intended for cocaine purchases. He and others involved then tried "an escalating series of tactics" to force Luna to repay the money.

Luna began hiding from them, Comey wrote, and they figured out a way to lure him on April 11, 2016, to Likquid Lounge, a bar owned by Tartaglione's brother in Chester.

Luna brought with him two nephews, Santiago and Miguel Luna, and a family friend, Gutierrez. Tartaglione and his co-conspirators did not allow them to leave.

Martin Luna was killed there later that afternoon while Tartaglione was still at the bar, Comey wrote.

According to Comey, Tartaglione then took Luna's body to property he rented at the time in Otisville. While he was gone, each of the other three men were shot in the head. The co-conspirators then took those three bodies to the ranch where they were buried with Luna's in a mass grave.

The bodies were not discovered until late December, a day after Tartaglione was arrested in the case. An autopsy did not determine an exact cause of death for Luna, only that he was the victim of "homicidal violence."

In June, Joseph Biggs, a school security officer from Nanuet, was also indicted in the killings.

Authorities have not said what Biggs' role was in the case. They have also been mum on whether one of the conspirators was Gerard Benderoth, a professional weightlifter and former Haverstraw police officer who was a friend of Tartaglione and Biggs.

In March, Benderoth killed himself in his car when he was pulled over by FBI agents investigating the quadruple homicide.

Comey did not specify how authorities knew of Tartaglione's whereabouts. She said that among the evidence turned over to the defense has been surveillance video from outside the bar, telephone records, cell tower records, license-plate reader records and text messages between the co-conspirators.

Prosecutors over the summer expanded on their earlier position that Tartaglione had not been the shooter by acknowledging to the defense that he was not even present when the shootings took place.

That prompted Bruce Barket, Tartaglione's lawyer, to request further evidence, particularly witness statements that typically are not turned over by prosecutors until the trial.

Barket argued that his client's role in the case has never been spelled out by prosecutors.

"Without knowing the underlying basis for and/or source of the government's conclusion that Mr. Tartaglione did not shoot the victims, and was not present for their shootings, the defense is unable to effectively address this powerful mitigation in its attempt to argue that the death penalty should not be pursued in this case, nor to adequately investigate this critical fact in preparing a defense," Barket wrote in his motion.

Prosecutors insisted that, other than Tartaglione leaving the bar, they had no evidence or witness statements clearing Tartaglione in the four deaths.

"The government maintains that, although Tartaglione was not present during the latter three murders, he is nevertheless responsible for them (as an aider and abettor)," Comey wrote.

Barket questioned whether prosecutors had any proof to back up their latest contentions.

"Little by little the case has been different (since Tartaglione was first arrested)," he said.

Twitter: @jonbandler