Emile Konig testifies during his father's trial in Honolulu, Hawaii, on Tuesday.

Emile Konig testifies during his father’s trial in Honolulu, Hawaii, on Tuesday.
Pool/KHNL/KGMB

The Hawaii doctor accused of trying to kill his wife on a birthday hike last year called his son over FaceTime, confessed to the attack and threatened to kill himself, his son testified in court Tuesday.

On March 24, 2025, Dr. Gerhardt Konig said “that he would not be making it back to Maui and to take good care of the younger kids,” Emile Konig testified. “(He said) that Ari, my stepmom, had been cheating on him and that he tried to kill her.”

Gerhardt allegedly FaceTimed his son again about an hour later and said he was going to jump off a cliff, but Emile told him not to do so. “I’m going to go before the police catch me,” Gerhardt said, according to the son’s testimony.

That was the last time he talked to his father, Emile Konig testified.

The details of the dramatic calls were revealed in a Honolulu courtroom during Gerhardt Konig’s trial on an attempted second-degree murder charge. Prosecutors allege the 47-year-old anesthesiologist shoved his wife, Arielle Konig, toward a cliff edge, tried to inject her with a syringe and bashed her head repeatedly with a rock during a hike in Oahu.

Arielle Konig, a nuclear engineer, testified last week about the “shocking” attack on the steep and narrow Pali Puka trail. She said she fought back and screamed for help until two fellow hikers arrived and intervened.

In the months before the hike, the couple had been going to counseling after she engaged in what she called an “emotional affair” with a coworker. She said her husband had planned the weekend trip from their home in Maui to Oahu to celebrate her 36th birthday.

The defendant has pleaded not guilty to the charge, which could come with a sentence of life in prison with the possibility of parole. His attorney, Thomas Otake, has described the incident as an “an unplanned, unanticipated scuffle” and said she attacked him first. He argued that she is giving false testimony in an attempt to get his money and house.

Gerhardt has two older children from an earlier marriage, and the couple also has two young sons. Arielle has filed for divorce, and their children are in her custody.

The prosecution rested its case on Tuesday after testimony from Emile and from Arielle’s parents. The defense is expected to begin calling witnesses on Wednesday. Gerhardt Konig may choose to testify in his own defense.

Son describes two FaceTime calls

Emile Konig said he was at home on Maui on March 24, 2025, when he got a FaceTime call from his father – who he referred to as “the defendant” – at 10:42 a.m.

On the call, Gerhardt confessed that he had tried to kill Arielle but said she had gotten “away,” and he said he planned to jump off the cliff, Emile testified.

His father appeared to be outside and was wearing sunglasses and a dry fit shirt, he said. The son asked about the splatters on his father’s shirt, and his father said it was Arielle’s blood, Emile testified.

Afterward, Emile testified, he went to his grandparents’ house nearby and told them about the call.

Emile said he received another FaceTime call from his father at about 11:46 a.m. Gerhardt asked if he had told anybody, and the son confirmed he had.

Gerhardt then repeatedly said he was going to jump off a cliff and said he had thought about suicide in the months leading up to the hike, the son testified.

“He said he was at the end of his rope,” Emile said.

Judith Mast, Arielle’s mother, confirmed in her short testimony that Emile came over and told them about the call that morning.

“He was very upset,” she said. “He was shaking, crying.”

She said she tried to call and text Arielle, and she tracked the location of her daughter’s phone to the trail. At 11:33 a.m., she texted Gerhardt, “Is Arielle ok?” He did not respond, she said.

The grandparents flew from Maui to Oahu to see Arielle in the hospital, she testified.

Arielle Konig was treated for severe lacerations and stayed at the hospital for one night. In her testimony, she said her recovery took about two to three months, and she showed the jury scars on her head and face.

Arielle Konig displays a scar on her forehead during her testimony in Gerhardt Konig's trial.

Arielle Konig displays a scar on her forehead during her testimony in Gerhardt Konig’s trial.
Pool/KITV

Gerhardt Konig was arrested on the day of the attack while trying to flee police, several officers testified earlier in the trial.