Robert Branch, speaking to reporters while flanked by his attorney, alleged that Detective Paul Ward put him in a bar-arm chokehold after following his vehicle off westbound Interstate 8 at College Avenue on May 4 about 5 p.m.
“I became afraid,'' Branch said, when Ward allegedly began to choke him.
Sheriff's spokeswoman Jan Caldwell said she couldn't comment on the claim, which is a precursor to a lawsuit.
“This matter has been referred to the District Attorney's Office, so I am not able to provide any information. However, this matter is under a thorough and exhaustive review with our internal Critical Incident Review Board,'' Caldwell said.
Branch claims that Ward -- driving an unmarked Ford sedan -- pulled up behind him about nine miles after Branch tried to pass the detective's car in El Cajon.
Branch said Ward -- dressed in civilian clothes -- threatened to arrest him for reckless driving, flashed a badge and demanded his license and registration.
According to his claim, Branch was afraid for his safety because he wasn't sure Ward was a law enforcement officer.
Branch, 25, said he started recording the encounter on his phone and was “incredulous'' that Ward hadn't called law enforcement.
Branch said Ward told him: “You are being detained,'' then grabbed him in a chokehold, cutting off his air flow.
The claim alleges Ward continued to choke Branch for about five more minutes.
At one point, a 9mm handgun fell out of Ward's ankle holster and was picked up by a witness, who called 911 and told an operator that he would hold onto the gun until police arrived.
As police sirens neared, Ward released Branch from the chokehold, according to the claim.
No criminal charges have been filed, according to attorneys handling the case.