ST. PAUL, Minn. (AP) — A former Minnesota state senator who was caught in a police sting operation pleaded not guilty Monday to a federal charge of attempted enticement of a minor for prostitution.

Justin Eichorn entered his plea in a brief appearance before Magistrate Judge Shannon Elkins. The judge granted his request for more time for his attorneys to review the evidence, so a trial that had been scheduled for June 9 will be rescheduled.

The 40-year-old Republican from Grand Rapids was arrested in Bloomington on March 17 after exchanging text messages with an undercover officer who posed as a 17-year-old girl and arranging a meetup for sex for money, according to court documents. Federal prosecutors then took over the case.

Eichorn was released to a halfway house in Duluth on March 26. A grand jury returned a felony indictment April 1. The charge carries a mandatory minimum sentence of 10 years.

Eichorn resigned from the Senate March 20. A special election to fill his seat is set for next Tuesday, April 29, between Republican Keri Heintzeman and Democrat Denise Slipy.