The family of an unarmed ex-con who was shot dead by cops as he resisted arrest during a Bronx traffic stop is planning a multimillion-dollar suit against the NYPD and demanding a criminal investigation, their lawyer said Saturday.

Allan Feliz, 31, who once served five years on a burglary conviction and who is the father of a 6-month-old boy, was shot in the chest Thursday as he tried to drive away from cops who were arresting him, video from the scene shows.

“We believe the police officer in this case should be indicted and we’re requesting that the DA investigate and convene a grand jury,” attorney Robert Vilensky told The Post.

“We are also suing the city for millions of dollars; we will be announcing that next week,” he said.

“We believe there is a shoot-to-kill mentality within the police in The Bronx,” he said, adding that less-than-deadly force should have been used against Feliz, who was at the wheel.

Feliz and his passenger were pulled over for allegedly driving without wearing seat belts, something the passenger disputes.

What cops characterized as “a substantial amount of drugs” was recovered, including apparent cocaine and heroin, Chief of Department Terence Monahan told reporters Thursday.

“The guy who was in the car with my brother told me that the barrel of the gun was aimed at him throughout the stop,” Feliz’s younger brother, Samy, told The Post Saturday.

“He told me that they were punching and elbowing my brother in the face as he was crying out in pain.

“He didn’t understand why [Feliz] was being beaten and [Tasered]. They treated him like an animal in the street. We know about what else has been going on in the Bronx. We confirmed from multiple witnesses and the guy in the car that he was wearing a seat belt so why was he stopped?”

“He was treated like an animal,” his mother, Mery Verdeja, cried, speaking Spanish with Samy acting as translator.

“I haven’t been able to sleep because I think of him being tossed around like a piece of meat on the floor,” she said, in reference to video showing Feliz being dragged, dying, from his car by police.

“He was so happy because of the birth of his son Eli,” she said of Feliz.

“He called me and told me he understood all of my worry for him and all of my insecurities. He recently had his son fall off the bed at home and it made him realize how loved he was” himself, as a child, she said.

“I should have died instead of him. No parent should have to bury their child.”