Around 7:30 p.m. Monday, George Arndt, 50, of Gale Lane went to the Sixth Street home of Kenneth Messemer, said Det. Lt. Gerard Pelkofsky. Arndt's ex-wife, Lisa Guzzardi-Arndt, was visiting Messemer, Pelkofsky said.
Arndt forced his way into Messemer's home, shouting that he was going to kill him, Pelkofsky said. Messemer shot Arndt twice with a licensed handgun, Pelkofsky said. Arndt, who was unarmed, "was attempting to attack Mr. Messemer," Pelkofsky said at a news conference in Yaphank Tuesday.
The two men had never met before. "This was the first time they've seen each other," Pelkofsky said.
Police said Arndt was on the kitchen floor with a fatal gunshot wound in the upper body when officers arrived Monday night. He was transported to Good Samaritan Hospital Medical Center in West Islip, where he was pronounced dead.
Messemer, 51, and Guzzardi-Arndt, 48, are friends, Pelkofsky said. Arndt and Guzzardi-Arndt have been divorced for about five years, though they lived together, he said.
As part of the investigation, authorities removed seven other licensed handguns and 29 long guns - rifles and shotguns - from Messemer's home, police said. The guns appear to be legally owned, Pelkofsky said.
No one has been arrested. The Suffolk County police Homicide Squad and the Suffolk district attorney's office are investigating.
"This is a very, very sad state of affairs," said Messemer's attorney Paul Gianelli of Hauppauge. "But Mr. Messemer was well within his rights to defend himself in his home."