They both left Richland to study at UW. Now he’s going to prison for killing her

A Richland High School graduate is going to prison for pummeling to death his 22-year-old girlfriend in an LSD-fueled rage.

Casey S. Henderson, 23, was sentenced Friday in a King County courtroom to 18 years and four months in prison.

The emotional hearing came almost two years after he brutalized Katy Straalsund, a Richland native who was months shy of graduating from the University of Washington.

“The pain I feel every day is crippling. I killed an important person in my life and it’s going to haunt me forever,” Henderson told Judge Veronica Alicea-Galván. “Katy was very special and I loved her. She was so kind, intelligent and eager to help people.”

“I admired her in many ways. We were always smiling and laughing, sharing some of the best times of our lives together,” he continued, reading from a statement. “I just wanted to make her happy. Now she’s gone and I wish it was me instead.”

Henderson cried as he told Straalsund’s loved ones that it hurts knowing how much pain and suffering he has caused everyone, said his attorney, Tim Leary of Seattle.

“I can’t imagine how terrible this has been for all of you,” added Henderson. “… I’m sorry. I’m sorry, and that’s all I can say.”

Nine people spoke in court on Straalsund’s behalf.

She and Henderson, also a UW student, had been dating for six months before she died.

Judge Alicea-Galván went with the prosecution’s sentencing recommendation at the top of the standard range. She could have gone as low as 10 years and three months.

King County prosecutors couldn’t be reached after Friday’s hearing.

Leary told the Herald they had hoped for something less than the 18 years, but also recognized that Henderson originally was charged with first-degree murder. That crime carried a mandatory minimum of 20 years.

The defense pointed out Henderson’s youth and lack of criminal history, and the fact that his paranoia in the violent attack was induced by LSD. He also took responsibility for the crime before putting everyone through a trial, Leary said.

“It’s a tragedy all the way around, and that’s what the court recognized,” he said.

Henderson pleaded guilty Jan. 9 in King County Superior Court to a reduced charge of second-degree murder with domestic violence.

After the plea, the Facebook page for the Katy Straalsund Memorial Foundation reminded people that there is “no excuse for abuse” and to choose “love over violence.”

“Domestic violence ends lives. It has to stop,” the post said. Her parents are Tracie and Eric Straalsund of Richland.

The foundation raises money for a memorial scholarship at UW in her name. Like Straalsund, the recipient would be a student of speech and hearing sciences interested in working with people with neurological communication disorders.

“Brain injury is a very real and serious consequence of domestic violence,” the foundation says on its Facebook page. “The scholarship will continue this dialogue and give a voice to Katy and others affected.”

Straalsund had anoxic brain damage after being repeatedly punched, kicked and strangled by Henderson on March 20, 2016. She died at Harborview Medical Center two days later from the severe head injuries.

She was a graduate of River’s Edge High in Richland and Columbia Basin College. She was a barista at Starbucks and planned to teach English in Spain after graduating from in June 2016.

Henderson told investigators that the couple took LSD together the day before the attack and he became paranoid.

“I became delusional and believed my life was in danger, thinking that attacking and killing Katy was the only option for survival,” he wrote in his police statement. “I’ve never experienced such extreme fear and panic before in my life, but I take full responsibility for her death. I shouldn’t have been using LSD to begin with, nor taken so much of it.”

Henderson’s Instagram account features earlier pictures of him using LSD blotters and others drugs. In one picture where he’s taking a hit, he says “Life’s a trip. Enjoy it.”

Her parents have disputed claims that she took LSD.

Police responded to Straalsund’s basement apartment after a neighbor reported hearing a man threatening to kill a woman for about 20 minutes.

When police arrived, Henderson had Straalsund in a choke hold. Investigators said he had punched her so hard that he’d broken his own wrist.

Straalsund had learned that Henderson was secretly dating another woman from South America, and that he had plans to move with her to Paris. His parents were living in Korea at the time he was arrested.

His mother spoke at Friday’s hearing.

Henderson has been locked up in the King County jail on $2 million bail since he was charged.

This story was originally published February 16, 2018 at 7:31 PM with the headline "They both left Richland to study at UW. Now he’s going to prison for killing her."