A longtime Los Angeles police SWAT sergeant is suing the LAPD, alleging the unit is run by a “SWAT Mafia” of veteran cops who encourage the use of deadly force and ostracized him for revealing its behavior.

Sgt. Tim Colomey, who spent 11 years as a SWAT supervisor until last November, filed a whistleblower lawsuit alleging retaliation for revealing that a group of veteran officers controlled the tactical unit’s operations and membership and punished him and others for speaking out.

Colomey said in the lawsuit filed Tuesday in Los Angeles County Superior Court that those leaders, who dubbed themselves the “SWAT Mafia,” “glamorize the use of lethal force, and direct the promotions of officers who share the same values while maligning the reputations of officers who do not.”

Colomey said those who use nonlethal measures to end standoffs and other contacts are pushed out.

“SWAT officers who have chosen not to use lethal force in suspect encounters, and who have instead sought to deescalate conflicts, have been ostracized and labeled ‘cowards’ by the SWAT Mafia,” the lawsuit says. “These officers will never succeed or promote within SWAT.”

His lawsuit did not cite specific examples of excessive force or unjustified killings by the SWAT unit. However, his attorney Diana Wells said the department’s internal affairs group was made aware of such incidents after Colomey provided specifics during an investigation.

Police Chief Michel Moore on Wednesday declined to comment, saying he had not seen the lawsuit.

Capt. Jonathan Tippet, who was in charge of the Metropolitan Division — which includes SWAT — during the time of the allegations, disputed some of Colomey’s characterizations.

“I disagree with the assessment,” he said of Colomey’s description of SWAT officers glamorizing the use of lethal force and ostracizing those who sought to de-escalate conflicts.

Colomey alleges that commanders “are aware of the serious and systemic problems that are linked to the SWAT Mafia’s power, but they have all turned a blind eye to these problems,” and that it has poisoned the entire unit.

The so-called Mafia, the lawsuit says, directs that “promotional positions ... be given to SWAT Mafia associates; control the selection of new officers entering SWAT based on who will kowtow to the SWAT Mafia.”

The SWAT accusations from Colomey come just a year after he was featured in a department podcast, “Born in Boston: A SWAT Story,” in which he told of surviving a near-fatal injury to rise to be a SWAT leader. He was riding with a partner, now Deputy Chief Dominic Choi, pursuing an armed suspect when he was hit by a car during a chase on foot.

Colomey, a 25-year-old LAPD veteran, has since become a familiar figure at SWAT scenes, often on the bullhorn negotiating with suspects holed up inside buildings.

Times staff writer Emily Alpert Reyes contributed to this report.