One of the country’s leading psychological experts on the maturity of the adolescent brain will be allowed to testify in the upcoming trial of a man accused of throwing the rock that killed Alexa Bartell. First Judicial District Judge Christopher Zenicek denied the prosecution’s motion to exclude the testimony of  Dr. Laurence Steinberg saying it is irrelevant to the case.

The Temple University professor is expected to argue that defendant Joseph Koenig’s brain was too immature to know the risk that his actions could kill someone the night he and two friends barreling down the highway threw large landscaping rocks head-on at multiple moving vehicles. 

Koenig, the alleged ringleader of the group, was 18 at the time. He was in court Thursday, as were his parents, who have been present for every hearing. On the other side of the courtroom were Bartell’s friends and family, who have also been present at every court proceeding.

Koenig is still facing a first-degree murder with extreme indifference and several attempted first-degree murder and second-degree assault charges related to other incidents that prosecutors allege he was involved in prior to Bartell’s death, according to court records. He has pleaded not guilty. 

At 10:17 pm, April 19, 2023, Bartell was on the phone with a friend, and the line went silent. Her friend tracked down her phone and drove to the location to find Bartell dead inside her car, which had drifted off of the roadway into a field. The large landscaping rock heaved at her yellow Scion was thrown with such force that it smashed through the front window, hit Bartell, and exited the back window.

After a search, investigators found the blood-stained rock on the side of the road.

This wasn’t the first time

First Judicial Chief Deputy District Attorney Katharine Decker argued that Steinberg’s assertions that adolescent brains lack the ability to control their impulses is “just an excuse.”

She pointed out that Koenig knew what he was doing because this was not the first time he had thrown rocks at moving vehicles. “It’s not as if the defendant hadn’t been engaging in this type of behavior for 3 months, on 10 separate occasions,” said Decker. She argued that testimony about undeveloped adolescent brains would mislead the jury. “The notion that adolescents take risks because they don’t know any better is ludicrous,” she said.

Koenig’s attorney, Tom Ward, disagreed, saying that science has shown that with no adults around, the adolescent brain is not mature enough to ignore peer pressure. “Hearing your friends laugh and cheer after you do something is a good example of reward,” he said. “Mr. Koenig’s age is a circumstance.”

In July, Koenig’s attorneys argued that an ADHD diagnosis qualified him for the insanity defense.

Bartell was 20 when she was killed.

The investigation

Investigators used cell phone data and crime reports to determine that the rock that killed Bartell was one of seven incidents of landscaping rocks that were thrown at vehicles in a large, semi-circular area stretching from Highway 72 in the south, Highway 93 in the east, Highway 128 in the north and Indiana Street in the west.

After an intense search, Koenig, Nicholas “Mitch” Karol-Chik, and Zachary Kwak,  were arrested several days after Bartell’s death.

Karol-Chik gave a four-hour video interview that night. 

In a hearing last July, Judge Christopher Zenisek ordered that Koenig undergo a mental health evaluation. Koenig’s trial dates were vacated due to the mental health evaluation.

As part of his ruling, he noted that not allowing the defense could result in a likely appeal and possible retrial. Because of backlogs with the state mental health system, according to testimony, Koenig’s evaluation was expected to take months. 

Each of the three suspects was initially charged with first-degree murder, but Kwak and Karol-Chick have pleaded guilty.

Last May 11, Kwak pleaded guilty to one count of first-degree assault, one count of second-degree assault, and an added count of criminal attempt to commit assault. 

Kwak told investigators he had only recently met Karol-Chik and Koenig, but he was complicit, according to a chilling statement to Jefferson County Sheriff’s deputies. Kwak said to them that, after they hit Bartell’s car, the three made a U-turn and drove by to see the damage that they had done. He told them he took a photo of the vehicle for a memento.

The next day, Kwak and Koenig vowed to stay mum about that night and came up with a corroborating story about what happened, according to the arrest affidavit.

Five days after Kwak took a plea deal, Karol-Chik pleaded guilty to three counts, including second-degree murder in Bartell’s death, and agreed to a sentence range of 35-72 years.

Prosecutors said that Karol-Chik was riding in the passenger seat and handed the “large rock that Koenig threw at Alexa Bartell, causing her death,” prosecutor Brynn Chase stated during the plea. “Karol-Chik knowingly engaged in conduct which created a grave risk of death.”

“Is that what happened?” asked First Judicial Judge Christopher Zenisek.

“Yes, your honor,” answered Karol-Chik. 

Koenig is the only one of the three who never gave an interview to investigators. Karol-Chik and Kwak gave conflicting information as to who threw the fatal rock during their interrogations, according to court testimony.

They are expected to testify against Koenig in his upcoming trial. That trial date has not yet been decided.

Zenicek set the defendant’s next motions hearing for Jan. 20, 2025.