SAN JUAN – Jeffrey Allen Weathers moved from Alaska to an oceanfront apartment in the Caribbean, but his new neighbors soon suspected the heavyset American hadn’t come for the sun. The FBI now says they were right.

Weathers, with convictions for sexual assault and possession of child pornography in his past, had moved to a small Puerto Rican town in the belief he could avoid registering as a sex offender and live without that stigma, an FBI agent wrote in an affidavit.

Weathers was arrested – thanks in part to his landlord – but law enforcement officials say other sex offenders share the perception that tropical Puerto Rico, where restrictions are less strict than in many U.S. jurisdictions, is an ideal place to hide.

Federal agents have arrested at least five other sex offenders over the last year for failure to register in Puerto Rico and sent them back to the U.S. to face prosecution on other charges, said Deputy U.S. Marshal Rafael Escobar.

He said the marshals are investigating 10 cases of unregistered offenders suspected to be on the island.

“I’m sure there’s a bunch more,” he said. “The Internet is there, and these guys are checking to see where the law is weakest.”

Each month, about half a dozen sex offenders come to the island from the U.S. mainland and do register with local authorities, according to Puerto Rico police Capt. Margarita George, who oversees the island’s sex offender registry. Nobody knows how many others fail to report in.

She said some are drawn by the lack of laws barring them from living near parks or schools – the sort of rules that have forced sex offenders to camp under bridges or in woods in parts of the U.S. And failing to register is a misdemeanor in Puerto Rico – not a felony as it is in most parts of the U.S. Some, like Weathers, find themselves colliding with federal rather than local authorities.

Offenders have told police they can do things in Puerto Rico that are nearly impossible elsewhere, such as buy property, George said.

“It is a fact that the guys who come down here know they’re not that strict,” Escobar said, though he said he did not know of any offenders from the mainland who committed new sexual offenses in Puerto Rico.

About 100,000 of the 714,000 registered sex offenders in the U.S. are unaccounted for, said Ernie Allen, president of the National Center for Missing and Exploited Children.

Puerto Rican officials are working with the U.S. Justice Department on legislation to meet the federal requirements.