A North Amityville man seemed delighted on a video shown Thursday to jurors to see the Suffolk detective who had him arrested and charged with murder in the death of his girlfriend.

Det. Thomas Walsh testified that the video showed Joseph DeFelice, 34, being processed at police headquarters in Yaphank after he'd been brought back from Florida, where he was arrested in October 2010.

DeFelice is on trial before Suffolk County Court Judge John Toomey Jr., charged with helping a friend kill his girlfriend, Mandy Jo Jenkins, 30.

"Hey, Tommy!" a smiling DeFelice said in the video when Walsh arrived at headquarters.

Because DeFelice now had an attorney, Walsh immediately held up his hands and told him, "We can't talk about the case."

"I know," DeFelice said, holding out his hand for Walsh to shake. "No hard feelings."

Weeks earlier, DeFelice had explained in detail his actions on Aug. 23, 2010, when Jenkins was killed, according to Walsh's testimony.

During questioning by Assistant District Attorney Robert Biancavilla, Walsh said DeFelice explained how he let his friend, David Newbeck, into his warehouse apartment to kill Jenkins.

Newbeck, 36, of Massapequa, wanted Jenkins dead because she had filed identity theft charges against his girlfriend, DeFelice said, according to Walsh.

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Newbeck wanted his girlfriend to be able to continue ripping people off so she could pay back a debt to him, Walsh said DeFelice told him.

Although DeFelice said he loved Jenkins, he said he felt he owed Newbeck, Walsh testified. Newbeck will be tried later.

In the police video, DeFelice later called an aunt in Florida and assured her the Suffolk detectives were looking out for him.

"They know I didn't do it either," he told his aunt. "They're good people. When it's all over, I'm coming home . . . Tell everyone I love them and I'll see them soon."

If convicted, DeFelice faces a maximum sentence of 25 years to life in prison.