The Hawaii doctor accused of trying to kill his wife took the stand Wednesday, claiming she attacked him first in a violent struggle on a Oahu hiking trail.

Gerhardt Konig is on trial for attempted murder for allegedly trying to kill his wife on March 24, 2025. On Wednesday he testified that on the day of the alleged attack, the couple had been hiking, something he said they often did together — as jurors were shown photos from the trip.

He told the court he chose the trail because it "seemed fun" after researching new hikes.

Konig said that after an argument about an alleged affair, he walked away, then returned to find his wife, Arielle, still on the trail, her demeanor suddenly changed.

He told jurors she was apologetic, said she didn’t want to ruin the day and suggested they work through their issues in therapy. The two even took a selfie.

Moments later, Konig said, everything shifted.

He testified he was standing on a ledge, trying to process what had just happened, when he felt what he described as a shove.

"When I turned around, I said, ‘What the f--- was that?’" he told the court.

Konig said he walked toward his wife, asking why she was screaming, and claimed she grabbed his wrists and pulled him to the ground.

He testified that during the struggle, she grabbed him by the genitals, adding that everything that followed happened "very quickly."

Konig said she then struck him on the side of the face with a rock.

Konig testified that he decided to jump and called his son, Emil, to say goodbye. Konig testified that he was not in a good state of mind when he called.

"He saved my life that day," he said through tears.

Konig told jurors he did not try to kill his wife that day — denying he shoved her off a cliff or attempted to kill her with syringes.

Earlier in his testimony, Konig described what he said was a sudden breakdown in what he believed was a "perfect" marriage.

He told jurors the relationship had been "fabulous," with no red flags, and that the couple planned to stay in Maui until their children graduated from high school.

Konig said he handled the family’s finances, describing himself as "a very meticulous person who keeps track of everything," and emphasized that everything they owned was shared.

But he said things changed after a trip his wife took to South Africa, when she failed to check in one night, something he described as unusual.

Konig testified he became suspicious of her relationship with a coworker, pointing to a different "tone," increased phone use, and behavior he described as secretive.

He said he later unlocked her phone while she was asleep and discovered hidden WhatsApp messages in a folder with notifications turned off.

According to Konig, the messages showed constant communication with a man in Maryland, including photos and song lyrics, before abruptly stopping after the South Africa trip.

He said the messages later disappeared entirely.

Konig testified that was the turning point — leading him to believe his wife was having an affair.

As he described the discovery, Konig became emotional.

"I didn’t know what to do," he said. "I was devastated."

Konig told jurors he later confronted his wife during a trip to San Luis Obispo, where she admitted the relationship was "completely inappropriate."

He said she had planned another trip with the man but canceled it and agreed to cut off contact outside of work emails. 

Konig also testified that he reached out to the man’s wife, telling jurors, "I felt if I was in her shoes, I would want to know."

Konig said he chose not to tell family or friends, saying he wanted to protect her.

Defense attorney Thomas Otake also questioned Konig about his background, including his previous marriage at age 20. The couple had two children, Ophelia and Emil.

Jurors also heard from additional witnesses.

Chuck Bussler, the owner of Fête Restaurant, testified that a reservation for Konig had been made through OpenTable for March 24, 2025, but was ultimately marked as a no-show.

Forensic pathologist Dr. Jonathan Arden testified that the victim’s head injury, while bloody in appearance, was not life-threatening and did not involve the skull or brain. He agreed it did not meet the standard for serious bodily harm and said the injuries were more consistent with two to three impacts, not up to 10 full-force blows.

On cross-examination, prosecutors highlighted Arden’s role as a paid expert who frequently testifies for the defense.

Prosecutors allege Konig attacked his wife on that hike, striking her multiple times in an attempted killing.

Konig has pleaded not guilty.