A transient man described by federal agents as a violent sexual predator at the time of his arrest in Portland in 2013 was sentenced Friday in U.S. District Court in Portland to two years in prison on a charge of failure to register as a sex offender.

Clyde M. Hall Jr., 50, had been listed as one of the U.S. Marshals Service’s 15 most wanted fugitives in the nation before his arrest on Oct. 3, 2013, when he was spotted walking near Portland City Hall.

Hall had been required to register as a sex offender due to three previous convictions for sex offenses – in 1989 in Androscoggin County Superior Court in Auburn for unlawful sexual contact and gross sexual misconduct; in 1999 in a Willsboro, New York, court for endangering the welfare of a child; and in 2000 in federal court in New York for possession of child pornography, according to court records.

According to the U.S. Marshals Service, Hall is a drifter who has been known to frequent school properties and watch children as they come and go from playgrounds. He was diagnosed as a sociopathic, psychosexual sex offender with a history of preying on women and children.

Authorities said Hall is sexually attracted to adolescent girls, and has an interest in younger boys. He has admitted to sexually abusing two 10-year-old girls and forcibly raping two women.

The U.S. Marshals Service said Hall served a 25-month sentence in North Carolina before he was released in March 2012. He was required to report to his probation officer and to a halfway house in Albany, New York. When he failed to report, the state of New York issued a warrant for his arrest.

Hall had been on the run since his release in North Carolina, and was added to the U.S. Marshals Service’s 15 Most Wanted List in September 2012.

He was featured on the “America’s Most Wanted” television program, in a show that aired in June 2012. The program detailed Hall’s violent history dating back to 1985. New York classified Hall as a Tier III sex offender – the most dangerous category.

Hall once lived in Maine, and at one time had family members living here. But authorities did not know why he chose to come here.

Hall told authorities after his arrest that he knew he was supposed to register as a sex offender, but didn’t, according to a prosecution document filed in federal court in Maine by Assistant U.S. Attorney Halsey Frank.

“He said that the federal system was a constant weight pushing him down,” Frank wrote.

Instead of going to a halfway house in Albany, where Hall was supposed to live after his release, he took a bus to New York City and then trains north to the Bangor area, where he lived for 18 months before getting caught, court records state.

After Hall’s arrest, he was first brought back to federal court in New York and sentenced to serve two years in prison for failure to register there, according to New York court records.

After completing that sentence, Hall was returned to Maine, where U.S. District Judge Nancy Torresen sentenced him on Friday to two more years for failure to register here. She also sentenced him to serve 10 years of supervised release after completion of his prison term.