BRENTWOOD — A Haverhill, Mass., man who allegedly claimed to be a federal agent before robbing a 25-year-old man has been indicted by a Rockingham County grand jury.

John Ruth, 48, is facing a felony count of false personation for allegedly posing as a law enforcement officer.

Ruth claimed to be a member of a “sex crimes task force” before robbing a man at a parking lot in Salem, according to police.

The victim thought he was meeting a 16-year-old girl from an online chat, but he was actually chatting with Ruth, police said.

Ruth also faces misdemeanor counts of false imprisonment and theft by unauthorized taking.

Prosecutors say Ruth met up with the man on Feb. 12 at a parking lot along Route 111 in Salem.

The victim complained to Salem police about being robbed of $146 in cash during an encounter with Ruth.

When questioned by police, Ruth admitted to meeting the victim, and “going online and posing as young girls to catch sexual offenders,” Officer Matthew MacKenzie said in a sworn affidavit.

The victim in the case was from Haverhill, Mass. Police do not know why Ruth chose New Hampshire to meet with the victim. No other victims from New Hampshire have surfaced.

Massachusetts State Police also questioned Ruth, who admitted to investigators “that he communicated with other subjects online” from his home in Haverhill, court records show.

Once the victim arrived in the parking lot, Ruth blocked him in with a blue rental car he was driving, police said.

Ruth approached the victim and ordered him to step out of his car, police said.

“Ruth searched him and his vehicle and told him he was a federal agent in a sex crimes task force,” MacKenzie said in the affidavit. “Ruth took a money clip and car keys from the pocket of (the victim) after frisking him.”

Ruth went to his car with the man’s car keys and money clip, pretending he was checking the man’s identification, police said.

Ruth returned the items a few minutes later — but without the cash, according to police.

The victim gave Ruth’s license plate number to Salem police. They tracked down the vehicle to a car rental company out of Haverhill, Mass.

The vehicle had been rented by Ruth’s 70-year-old mother, according to police.

The mother told police that her son had the rental car after he dropped her off at the airport.

Ruth remains free on bail.

jkimble@newstote.com