An anesthesiologist from Hawaii has been convicted of attempting to kill his wife by striking her with a rock during a hike for her birthday last year.
A jury in Honolulu found Gerhard Koenig guilty on a misdemeanor charge of attempted manslaughter related to the incident involving his wife, Ariel Koenig, on March 24, 2025. This altercation occurred after a discussion about an affair while they traversed the Pali Puka Trail on Oahu.
Initially charged with attempted second-degree murder, the judge provided the jury with the option for a lesser charge. After deliberating for more than eight hours, they reached their verdict.
The jury was given instructions to consider other charges, including attempted manslaughter and various degrees of assault if they couldn’t convict Koenig of attempted murder.
As the verdict was read, Gerhard, 47, bowed his head, facing up to 20 years in prison due to the incident being classified as involving extreme mental or emotional impairment.
Ariel recounted Gerhard coldly stating, “Fuck, I’m done,” followed by attempts to push her off the cliff and eventually hitting her on the forehead with a rock during a struggle.
The 37-year-old mother, also a nuclear engineer, was saved when two women heard the commotion and intervened, finding Gerhard on top of her, covered in blood and crying.
During closing arguments, prosecutor Joel Garner highlighted that the force of Gerhard’s swing caused pieces of the rock to embed in Ariel’s scalp, suggesting that the only thing preventing further harm was their being caught in the act.
Gerhard maintained that the conflict began when Ariel, while trying to take a selfie, endangered herself and that he was acting in self-defense when he struck her. He claimed Ariel was pulling him down when he defended himself, insisting he didn’t have a syringe during the confrontation.
The defense attorney, Thomas Otake, argued that prosecutors had misrepresented the case and selectively gathered evidence to back their claims, stating that the “he said, she said” nature of the case left reasonable doubt.
Throughout the three-week trial, the prosecution suggested Gerhard grew violently abusive after discovering Ariel had developed emotional ties with a co-worker, Jeff Miller, following his hacking into her phone.
According to testimonies, after discovering three months’ worth of messages between Ariel and Miller, intimacy in their marriage diminished significantly as they attempted to repair their relationship.
Ariel portrayed Gerhard as controlling and overly demanding in their physical relationship, insisting on frequent contact that she was uncomfortable with.
Their son, Emil Koenig, testified against his father, claiming Gerhard confessed to him over FaceTime about attempting to kill Ariel after accusing her of infidelity.
Ariel has since filed for divorce.
