SOUTH BEND, Ind. — The former owner of a northern Indiana tanning salon pleaded guilty to charges Monday for using his phone to secretly film naked women while he gave them spray tans.

Albert Reasonover, 51, pleaded guilty to three counts of voyeurism and one count of obstruction of justice under an agreement with prosecutors in which they dropped a child exploitation count.

Prosecutors say Reasonover secretly recorded three customers, including one who was under age 18, between January and April at the former Tiki Tan salon in Granger.

While spray-tanning a woman, Reasonover used his cellphone to record nude images of her without her consent, investigators said. Under Indiana law, felony voyeurism occurs when a person uses a camera to spy on someone who they expect to be naked.

The woman had used her own phone to record video of her spray-tan session, and it captured Reasonover pulling out his phone to record the woman after she closed her eyes, according to charging documents. Police later found evidence that Reasonover filmed two other women. He was arrested April 29.

The obstruction of justice charge stemmed from Reasonover deleting messages and photos from his phone after learning of the allegations against him.

Under the terms of the plea agreement, Reasonover would serve at least one year in prison for each of the three voyeurism charges, said Jessica McBrier, a spokeswoman for the St. Joseph County Prosecutor’s office. He also could serve up to 2½ years in prison for the obstruction count.

St. Joseph Superior Court Judge John Marnocha is scheduled to sentence Reasonover on Nov. 2.