A 33-year-old Honolulu man who advertised himself as a photographer was sentenced to 15 years in prison Tuesday for using the internet to try to have sex last year with a 15-year-old girl.

Dustin Miyakawa also was sentenced by federal Judge Derrick Watson to 20 years of supervised release.

“This 15-year sentence reflects the seriousness of Miyakawa’s criminal conduct and sends a powerful message to child sex predators in our community about the consequences of their criminal behavior,” U.S. Attorney Kenji Price said.

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 says Miyakawa solicited girls on his Instagram account.

Miyakawa admitted in June 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.

Federal investigators say Miyakawa told the girl he was a Hono­lulu Magazine photographer, 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.

Price said Tuesday’s sentencing is part of new campaign to expand child exploitation enforcement, an effort that has produced far more charges for such crimes this year than in any single calendar year from 2016 to 2018.

Last Wednesday, part-time Maui resident George Alexis Theros pleaded guilty to sexually assaulting a 14-year-old from Thailand that he “adopted” five years ago.

“When I announced the charges against Miyakawa last year, I said the sexual exploitation of minors as a general matter is intolerable. And pursuing these cases for federal prosecution is a high priority of my office,” Price said.

“As the Miyakawa and Theros prosecutions demonstrate, I meant what I said. And today every child sex predator in Hawaii should know that my office will continue to create a path for you to find a home in federal prison,” Pricesaid.