Former Marine Capt. Michael Arpaio has turned up in San Juan, Puerto Rico, where he moved in an apparent attempt to avoid registering as a convicted sex offender, records show.

What's more, Arpaio now finds himself on the verge of losing his freedom once again after pleading guilty to a role in a carjacking conspiracy that led to the death of a cocaine courier on the island in 2008.

Arpaio, 37, appeared to drop off the face of the earth in 2004 after he finished serving a 15-month sentence for molesting boys at The Citadel summer camp between 1995 and 2001. The former cadet didn't show up on the national sex offender registry, and no one at the school seemed to know what became of him.

Questions about his whereabouts became more urgent after a sixth former camper filed a lawsuit against Arpaio and The Citadel on Nov. 18, alleging he was sexually molested by the ex-Marine. Attorneys have indicated that at least one more suit against Arpaio is on the way.

A search of public records and court documents led The Post and Courier to Arpaio's September 2008 indictment in Puerto Rico for failing to register as a sex offender.

Arpaio was required to register as a result of his June 2003 guilty plea in military court to charges of indecent assault on a minor, inappropriate conduct of an officer and sodomy with a minor, court records show. He didn't register in his native Georgia after he was released and then spent four years avoiding detection in San Juan, where he became part-owner of a restaurant, court records show.

In January 2009, Arpaio pleaded guilty to a charge of failing to register and was sentenced to 15 months in prison. He was serving that sentence when he was indicted in the carjacking plot, records show.

Arpaio and 11 other men -- including two police officers and a former law enforcement officer -- were accused of staging a phony traffic stop in May 2008 to rip off a man who they knew was carrying almost 31 pounds of cocaine, according to the FBI. After "arresting" the man, the group took him in handcuffs to an auto repair shop for further interrogation. Arpaio then allegedly helped steal drugs, money, watches and a gun from the victim's home, according to federal court records.

The man was later strangled, court records show.

Arpaio pleaded guilty last year to aiding and abetting in the crime but has not been sentenced, according to court records.

FBI officials and prosecutors in San Juan did not return phone calls last week seeking information on the case. Arpaio's attorney, assistant federal public defender Yasmin Irizarry-Pietri, had no comment other than to confirm she represented Arpaio in both cases in Puerto Rico.