Big Island man sentenced to 40 years after pleading guilty to sexually assaulting 2 teen girls

A man from Mountain View was sentenced to a 40-year prison term after pleading guilty to sexually assaulting two teenage girls between February and May 2025.

Joseph Donald Tibbs, 45, appeared in Hilo Circuit Court on Wednesday, where Judge Peter Kubota passed sentencing. He has remained in custody since his arrest on May 29, 2025, after a months-long collaborative investigation between the law enforcement Internet Crimes Against Children task force, the Hawai‘i Police Department, the Hawai‘i County Office of the Prosecuting Attorney and Homeland Security Investigations.

Tibbs pleaded guilty in July 2025 to two counts of first-degree promotion of child abuse and four counts of first-degree sexual assault. On Wednesday, April 15, Kubota also required that Tibbs register as a sex offender.

“It is my hope that yesterday’s sentencing sends a powerful message to those who betray family trust and prey upon our keiki, that they too will be held accountable for their actions,” said Prosecuting Attorney Kelden Waltjen in a press release Thursday, April 16.

Tibbs initially faced 15 charges, which included incest, second-degree promotion of child abuse and use of a computer in the commission of a separate crime. These charges were dismissed at sentencing as part of the plea agreement, Hawai‘i County deputy prosecuting attorney Annaliese Wolf told Big Island Now following Tibbs’ guilty plea.

Tibbs was in a position of trust over the girls, who are between the ages of 14 and 16, Wolf said.

“This case still rates easily as the most horrific sexual abuse case that I’ve ever seen,” Wolf said, who has been in the position for 15 years and has handled a “significant number of sex assault cases and as of late, child pornography cases on this island.”

Waltjen recognized the hard work of the investigators, Wolf and the victim advocates in the case.

“Through strong collaboration and shared investment into protecting our community, we will continue to prioritize the identification, investigation, and prosecution of those who sexually abuse and exploit children,” he added.