A former Oahu schoolteacher — initially discovered by FBI agents to be exchanging messages containing child pornography with a Philadelphia teacher — was sentenced Wednesday to 30 years in prison for sexually assaulting a 13-year-old former student and promoting child abuse.

Oahu Circuit Court Judge Fa‘auuga To‘oto‘o sentenced 35-year-old Alden Bunag to 20 years in prison for continual sexual assault of a minor under the age of 14, a Class A felony, and 10 years for second-degree promoting child abuse, a Class B felony, to be served consecutively.

He also sentenced Bunag to five years in prison for third-degree promoting child abuse, which will run concurrently with the 20-year sentence.

Bunag took a plea deal in March, pleading guilty to the three charges, but the state dropped one count of first- degree promoting child abuse, a Class A felony, on the original indictment, which referred to the production of child pornography.

Bunag admitted to continuous sexual assault of a minor for having engaged in three or more instances of sexual acts from Aug. 1, 2016, to and including Sept. 27, 2017, with a boy under the age of 14. The boy, born in 2003, turned 18 in 2021, the indictment says.

Bunag also pleaded guilty to disseminating child pornography between Nov. 10, 2019, and June 15, 2022, and possessing child pornography Nov. 10, 2019, to June 15, 2022.

After the sentencing, Bunag was returned to federal custody to serve the remainder of a 17-1/2-year federal prison sentence for producing child pornography.

The judge ruled that the 30-year sentence will run concurrently with any other sentence he is currently serving, which includes the federal sentence.

After he serves his 17-1/2 years in a federal facility, he will be turned over to the custody of the state to serve the remainder of his 30-year state sentence, a spokesman for the Honolulu Prosecutor’s Office said.

“Bunag is not only a sexual predator, but a former intermediate school teacher who preyed on one of his students,” Honolulu Prosecutor Steve Alm said. “The circumstances of the case as presented by Deputy Prosecutor Ayla Weiss convinced Judge To‘oto‘o a lengthy sentence was warranted.”

Alm thanked the FBI, U.S. Attorney’s Office, Honolulu police and the judge for their work “in bringing this defendant to justice.”

In the June 2022 federal complaint, Bunag allegedly told a Philadelphia schoolteacher in online chats that he had sex with a 13-year-old former student during lunch breaks at school.

Honolulu FBI agents arrested Bunag on June 15, 2022, at an Oahu high school where he worked as a summer school teacher, the complaint said.

A Department of Education spokeswoman said shortly after his arrest Bunag was not a salaried employee, but most recently held a part-time temporary teaching position at Pearl City High School, where he held a permanent secondary teaching position from 2020 to 2021.

He also was a part-time substitute teacher at Ilima Intermediate School from 2016 to 2017.

Bunag also taught dance and ran a photography business, taking senior high school and family photos, the complaint said.

Bunag admitted during a voluntary interview with FBI agents to having sex multiple times with the 13-year-old boy, and used camera equipment to record encounters with the boy and other minors, sharing them with the Philadelphia teacher.

But federal prosecutors did not charge him with the sexual assault because that does not fall under the U.S. Justice Department’s jurisdiction.

FBI agents in Philadelphia, acting on an online tip, discovered what the complaint alleges were more than 3,392 messages included hundreds of images and video files of child pornography between the Philadelphia teacher and Bunag.

Bunag negotiated a plea deal with federal prosecutors, who agreed not to pursue charges related to material found on his electronic devices seized by the FBI.

He pleaded guilty May 19, 2023, to producing child pornography.

In addition to his prison sentence, U.S. District Judge Susan Oki Mollway also ordered him to pay $30,000 in restitution, and ordered him to be placed on 15 years of supervised release.

Victims of sexual abuse are urged to contact the Sex Abuse Treatment Center at 808-524-7273 or Rape, Abuse &Incest National Network at 800-656-4673. In case of emergency call 911.