A murder defendant who opened fire in a slaying caught on video testified Wednesday that the man he shot in Elmont had talked about a gun and killing people "for a living."

"Everybody has to understand, this happened fast," Wilfred Labossiere, 33, told jurors.

The Far Rockaway mechanic testified that commotion broke out as he argued with victim Christopher Mullings, whose family has said was an Army veteran.

"It was chaos. Bodies were moving. Things were happening at the same time," he testified. He recalled being punched as he ran out the door of the home where the shooting happened.

Other witnesses have testified that Mullings, 29, a father of two who lived in Roosevelt, was unarmed when he died in the November 2012 shooting.

The defense claims Labossiere shot Mullings in self-defense, and the defendant also testified Mullings made a move for his own pocket after mentioning a gun. Labossiere faces up to 25 years to life in prison if the jury convicts him of second-degree murder.

advertisement | advertise on newsday

The gunfire also wounded Sandra Clarke, the maternal grandmother of Labossiere's son, who has testified she tried to break up the dispute at her home before gunshots rang out.

Testimony showed the argument started after Labossiere found out the mother of his 3-year-old son had been paying Mullings' brother to baby-sit the boy at the home.

Mullings' brother pulled out his new iPhone to record the argument and video was rolling when the shooting happened.

The video, played for jurors last week, appears to show an argument before Labossiere draws a gun outside the home and shoots two people by the front door.

Labossiere also testified he didn't believe he could safely retreat to his car. But he said during a cross-examination he never told anyone at the hospital where he brought Clarke that there was someone at her house who needed help.

Labossiere said he was suicidal in the aftermath because Clarke could have died and not because he felt any guilt.

Lawyers will make closing arguments at Nassau County Court in Mineola Thursday.