David Newbeck convicted in 2010 Mandy Jo Jenkins murder in North Amityville

A Massapequa man was convicted Wednesday of shooting a North Amityville woman to death after she refused to withdraw an identity theft charge against his girlfriend.

David Newbeck, 36, was impassive as he heard the jury foreman pronounce him guilty of second-degree murder and first-degree hindering prosecution, for killing and then hiding the body of Mandy Jo Jenkins, 30, on Aug. 23, 2010. Meanwhile, Jenkins' sister, Crystal Buturla, nodded in satisfaction.

Last fall, Jenkins' boyfriend, Joseph DeFelice, was convicted of his role in the murder. Suffolk prosecutors said DeFelice let Newbeck into the warehouse apartment he and Jenkins shared. While DeFelice took his Rottweiler for a walk, Newbeck shot Jenkins four times in the head and once in the chest. Newbeck then dumped the body in Lindenhurst while DeFelice cleaned the blood-spattered bedroom.

"This is our ultimate goal -- to get them convicted, to have justice," Buturla said afterward. "Mandy would always get the last word, and she got the last word today. She would never back down."

Jenkins' sister-in-law, Marie Castiglione, said the family was thankful to the jurors, who took five hours to reach a verdict. Jurors declined to comment.

Newbeck was found not guilty of criminal possession of a firearm. The .45-caliber handgun used to kill Jenkins was never found.

Defense attorney William Keahon said the acquittal on the gun charge could undermine the murder conviction because it is "inherently self-contradictory." He predicted an appeals court is "going to mandate a new trial."

The trial lasted more than a month and included 52 witnesses, more than 300 exhibits, a 10-day interruption after Keahon fainted during his closing argument and what Keahon called "a parade of characters" -- witnesses with criminal records -- who testified about how Newbeck bragged about the killing to them.

But Assistant District Attorney Robert Biancavilla told jurors in his summation, "They're not my characters. They're his characters," pointing at Newbeck.

Biancavilla showed how surveillance video and cellphone location data showed Newbeck moving to the crime scene and where he dumped the body, but he said his best evidence was recorded jailhouse phone calls of Newbeck discussing the crime with his mother.

"David Newbeck is my star witness," Biancavilla told jurors. "You could not ask for anything better than this."

There was only one possible verdict jurors could reach, Biancavilla said afterward. "They followed the evidence to its logical conclusion," he said.

Newbeck faces a maximum of 25 years to life in prison. Suffolk County Court Judge John Toomey Jr. will impose sentence on June 23 -- what would have been Jenkins' 34th birthday.

"How cool is that?" Biancavilla said when Buturla told him.