PORTLAND, Maine — A former Wells man has been sentenced to prison for failing to register as a sex offender.

Robert Wayne Lyon, 27, formerly of Wells, was sentenced to 18 months in prison, followed by five years of supervised release, in U.S. District Court in Portland, U.S. District Attorney Thomas Delahanty III announced Tuesday.

Lyon pled guilty to the offense on Oct. 29, 2013.

According to court records, in 2007 Lyon pleaded guilty in Arizona to sexual conduct with a minor, a crime that required him to register as a sex offender under state and federal law upon his release from jail. In 2009, when Lyon updated his registration in Arizona, he acknowledged that he understood his obligation to register as a sex offender was a lifetime requirement and that if he moved to another state, he had to comply with the registration requirements of that state.

Soon thereafter, Lyon left Arizona and moved to Arkansas and then Missouri before arriving in Maine in 2012.

Authorities say Lyon never registered as a sex offender in any of those states.

He was arrested by federal authorities on July 2, 2013.

The case was investigated by the Wells Police Department and the U.S. Marshals Service.