Probe to determine what led to cop's death

Nassau police are investigating whether a retired New York City cop's shouted warning of a gun prompted an MTA police officer to fatally shoot a plainclothes Nassau officer who had arrived at a crime scene carrying a rifle.

Police interviews of the former NYPD officer and a dozen or so Nassau officers continued Monday as detectives tried to unravel the chaotic minutes surrounding the shooting of Officer Geoffrey J. Breitkopf.

The "friendly fire" shooting Saturday night came minutes after other officers had shot and killed a knife-wielding suspect in his Massapequa Park home.

Breitkopf, 40, a veteran member of the elite Bureau of Special Operations, was walking toward the house when an MTA officer identified by sources as Glenn Gentile -- one of two transit officers at the scene -- shot him at close range.

Nassau Police Benevolent Association President James Carver said the retired city officer mistakenly believed Breitkopf was a threat.

"He yells, 'He's got a gun' or 'gun, gun,' or words to that effect," Carver said, "and that's what alerts the MTA guys." Carver said that account came from Nassau officers who were at the house.

A department source confirmed there was a shouted warning about a gun, but investigators are still trying to determine whom it came from.

Nassau police spokesman Det. Lt. Kevin Smith said only the shooting is still under review, including "any part" played by the ex-city officer, whose name was withheld, and "what his observations were."

Neither MTA cop ordered Breitkopf to stop or drop his weapon in the brief moments between the shouted alert and the shot, Carver said. Smith, citing a continuing investigation, said he could not confirm there was no verbal warning.

Nassau police union officials Monday sharply criticized the MTA officers, as well as the retired city officer. All of them, the union said, played a role in the department's first cop-on-cop shooting death since 1976.

"There were three people there who had no business being there, and that's what precipitated this," Carver said. He called on department brass to "remind" other agencies to "take their direction from Nassau police" when their officers respond to crime scenes in the department's jurisdiction.

MTA officials declined to respond to the criticism.

It remained unclear whether Breitkopf wore any visible police identification.

A Nassau department source said that in the moments after the shooting, officers rushing to try to save Breitkopf's life stripped off some of his clothes. Breitkopf's badge, strung on a chain, was later recovered along with his clothes and weapons, but it was not certain whether he had worn the badge outside his clothes.

The tragic chain of events began at 8:13 p.m. Saturday when police received the first of a series of 911 calls -- at least two placed by the retired officer -- of a masked man, later identified as self-described Satanist Anthony DiGeronimo, threatening people with knives.

Nassau patrol officers arrived and followed DiGeronimo, 21, into his Fourth Avenue home. He ran into his bedroom, and two officers requested backup. DiGeronimo then rushed out "with a knife raised over his head in an attack position," Smith said. Both officers fired, killing him.

Several minutes later, a "slow down" alert on the police radio signaled the situation was under control. The retired city officer remained outside the house, Smith said.

As many as 14 Nassau officers were in and around the home. The two MTA officers who responded from the nearby LIRR station were also out front, police said, as Breitkopf and a partner parked their vehicle. With his partner following at a short distance, Breitkopf walked past several officers and across the lawn toward the front door, a black M4 assault rifle on a sling under his right arm, the barrel pointed at the ground.

Nassau officers and Bureau of Special Operations union representative John LaSala said Breitkopf was well known to patrol officers and "obviously an accepted part of the scene" as he walked unchallenged toward the house.

It was at this point, according to Carver, that the retired officer yelled the gun warning.

Officers at the scene reported seeing one MTA officer grab Breitkopf by the left arm, partially spinning him in an apparent attempt to stop him, as Gentile drew a weapon and fired at a distance of less than five feet, Carver said.

The bullet struck Breitkopf below his right armpit, tore through his chest cavity, and lodged in his left arm. The Selden resident and married father of two children was later pronounced dead at Nassau University Medical Center in East Meadow.

MTA officials declined to answer questions about the shooting yesterday.

"The MTA Police Department, and the MTA officer involved in Saturday's shooting, are fully cooperating with Nassau County Police Department's investigation," the agency said in a statement.

Gentile, 33, of Holtsville, a five-year veteran of the force and the son of a former Nassau police detective who died in 2007, is now on sick leave, according to an MTA spokesman.

With Alfonso Castillo