A Biddeford man accused of bringing a woman in her late 50s from Maine to prostitute her in New Hampshire changed his plea to guilty on Tuesday in U.S. District Court in Portland to an interstate pimping charge.

Leo Grondin, 48, had initially pleaded not guilty on Sept. 1 after being indicted by a federal grand jury last month on a felony charge of transporting an individual in interstate commerce with intent that she engage in prostitution.

But Grondin reversed his plea before Judge Nancy Torresen as his Oct. 5 trial date approached.

Grondin had been in federal custody since his arrest on July 23 and will remain in custody pending his sentencing hearing. His sentencing date was not immediately available.

Biddeford police got a tip in the case against Grondin on July 9, when the daughter of the woman in her 50s called to report that she had discovered emails about prostitution on her mother’s cellphone and that her mother admitted when confronted about the emails that Grondin was prostituting her and other women, according to court records.

Police tracked Grondin and the mother to a hotel in Dover, New Hampshire, on July 17 after discovering another online advertisement with Grondin’s phone number and a picture of the mother. Police took Grondin into custody there on an outstanding arrest warrant issued by New Hampshire authorities. The woman agreed to let police give her a ride back to Maine and tell them about the prostitution business, court records state.

Grondin faces 10 years in federal prison and a fine of as much as $250,000.