PORTLAND, Maine — A Portland man was sentenced in federal court Wednesday to 15 months in prison and five years of supervised release for failing to register as a sex offender.

Darrell Lee Roath, 43, who pleaded guilty to the charge on Aug. 29, had been convicted in Texas of indecency with a child in 1988, according to the U.S. attorney’s office. The crime required him to register as a sex offender whenever he changes residences.

He moved to Maine in 2009 but failed to register as a sex offender in this state. When he was interviewed by investigators last December, he acknowledged that he was required to register but had not done so, the U.S. attorney’s office said.

U.S. District Judge Nancy Torresen imposed the sentence on Roath.

The investigation was conducted by the U.S. Marshals Service and Scarborough police.