U.S. Marshals have arrested a Tucson man who failed to register as a sex offender and allegedly had been impersonating a law enforcement officer. Steven Robertson was taken into custody at a Tucson motel on Thursday, August 14.

According to investigators, Robertson was released from the Arizona Department of Corrections on July 28 and failed to register as a sex offender as required by law. Early in August, Robertson met a woman on a telephone chat line who came to Tucson to meet him. While in town she became ill and was admitted to St. Mary’s Hospital. Investigators say Robertson then contacted the hospital impersonating a Deputy U.S. Marshal and said he had a warrant for the woman’s arrest.

“We take very seriously any attempt by individuals to falsely portray themselves as a federal law enforcement officer,” said David Gonzales, U.S. Marshal for the District of Arizona.

Robertson is in the Pima County Jail on a state charge of failing to register as a sex offender. Prosecution by federal authorities on a charge of impersonating a federal officer is pending review.