Friday | June 24, 2016
About Us | Contact | Subscribe

Details emerge in slayings of mother, daughter


Tribune-Herald staff writer

A Hilo man accused of the shotgun slayings of his girlfriend and her mother told a 911 dispatcher “he felt that his ‘girlfriend was cheating’ on him, and that her ‘mother hated’ him,” according to court documents filed by police.

Documents state that on the morning of Feb. 11, Sean Ivan Masa Matsumoto was taken by ambulance to Hilo Medical Center “after he requested medical assistance due to not feeling well after taking medication and experiencing anxiety.” The 34-year-old Matsumoto’s visit to the emergency room was at 9:43 a.m., more than 13 hours prior to the fatal shootings of Matsumoto’s girlfriend, 45-year-old Rhonda Lynn Alohalani Ahu, and her 74-year-old mother, Elaine Ahu, at their home at 612 Leilani St.

Documents state that police obtained 41 pages of medical records documenting Matsumoto’s emergency room visit. Those records have not been made public. An inventory of drugs prescribed to Matsumoto found at the home lists the anti-anxiety drug alprazolam, which is marketed as Xanax, escitalopram, an anti-depressant marketed as Lexapro, plus pills and inhalers for asthma or chronic obstructive pulmonary disease, and medication for type-2 diabetes. Also found was an empty pill bottle dated Jan. 8 with a label indicating 20 7.5-milligram tablets of hydrocodone with acetaminophen, a semi-synthetic opioid painkiller marketed as Vicodin.

According to documents, an officer who arrived at the home at 11:27 p.m. found Matsumoto “pacing back and forth in the driveway … while talking on a green colored cellular phone.” The officer ordered Matsumoto to raise his hands above his head and to lie face down on the driveway, and then handcuffed Matsumoto, documents state. The officer reportedly found a spent .12-gauge shotgun shell on the ground next to Matsumoto.

Rhonda Ahu’s body was found in a recliner in the living room; Elaine Ahu’s body was found on the floor in a bedroom. Both had been shot in the head and face. A .12-gauge Mossberg shotgun with a pistol grip handle was found on a love seat in the living room next to the front door, documents state.

Two children, Matsumoto’s and Rhonda Ahu’s 6-year-old son, and Rhonda Ahu’s 15-year-old daughter from a previous relationship, were in the home at the time of the shooting, police said, but neither were physically harmed.

According to documents, Rhonda Ahu’s daughter told police that she was in her bedroom and heard a gunshot coming from the living room. She said she saw Matsumoto walking down the hallway to her grandmother’s bedroom and heard Matsumoto tell Elaine Ahu “this is for all the years the way you guys treated me” before shooting the woman. She said “she saw her grandmother fall onto the floor after being shot with the shotgun by Sean Matsumoto,” police wrote. She said that Matsumoto “then came to her room and took her green colored cellular phone.” She told police she then went next door to her aunt’s home.

Matsumoto’s and Rhonda Ahu’s son “appeared to have just woken up” when police entered the home, documents state.

Earlier court documents filed by police stated that Matsumoto had called 911 “to report that he just shot two people in his residence.” Matsumoto reportedly told responding officers, “I’m sorry, I know I had the gun in my hand,” and asked, “Is my son OK?”

Matsumoto has pleaded not guilty to first-degree murder, two counts each of second-degree murder and use of a firearm in the commission of a felony, three other firearms offenses, and reckless endangering. He’s scheduled to face trial July 15 at 9 a.m. before Hilo Circuit Judge Greg Nakamura. A first-degree murder conviction would mean a mandatory sentence of life without the possibility of parole.

He remains in custody without bail at Hawaii Community Correctional Center.

Email John Burnett at


Rules for posting comments