A 33-year-old Honolulu man who advertised himself as a photographer pleaded guilty Tuesday in U.S. District Court to using the internet to try to have sex last year with a 15-year-old girl.

Dustin Trey Miyakawa faces a prison term of 10 years to life at sentencing in October.

In exchange for his guilty plea, the government promises to drop two other charges accusing Miyakawa of child sex trafficking; for transporting the girl in his car to his apartment where he tried to have sex with her; and the attempted production of child pornography, for taking topless photographs of the girl. The government also promises not to charge Miyakawa with crimes connected to similar incidents in January 2015 and May 2016 involving two other underage girls.

At the time of his arrest in May 2018, Miyakawa was on probation for 2006 convictions in Washington state for offering an 11-year-old girl $500 at her middle school to make out with him and offering a 14-year-old girl $200 near her high school.

The government promises that if Miyakawa is resentenced to jail or prison for the Washington state crimes, it will recommend having him serve his federal prison term at the same time.

Miyakawa admitted Tuesday that he met a 15-year-old girl on Instagram in March last year and offered to take pictures of her to help her start her modeling career. He said he picked her up, took her to his apartment and offered her money for sex. When the girl refused, he threatened to share with others topless pictures he took of her. The girl still refused and left.

The government says Miyakawa solicited girls on his Instagram account studio2photography and website studio2.photography.smugmug.com. Federal investigators say Miyakawa told the girl he was a professional photographer for Hono­lulu Magazine, asked her age and pressured the girl into posing for topless photographs. They said Miyakawa used the topless pictures to try to blackmail the girl for sex after she refused his offer of money.

The girl in the January 2015 incident told police that after she refused to have sex with Miyakawa and left his apartment, she found nude pictures of her on his website.