KRON4’s Amy Larson is in court daily to bring you updates on the trial of Nia Wilson‘s killer. Find all her stories here.

OAKLAND, Calif. (KRON) — The Nia Wilson murder trial’s first verdict is all but certain: Guilty.

Alameda County Deputy District Attorney Butch Ford, defense attorney Christina Moore, and even John Cowell himself, admitted to the jury that Cowell stabbed Wilson and her sister on a BART train in 2018.

The jury’s second verdict remains the uncertain factor: was Cowell insane or sane at the time he killed Wilson?

By Reason of Insanity

Cowell has pleaded not guilty by reason of insanity for killing a teenager whom he had never met. Nia Wilson disliked taking BART for transportation, but she rode a BART train on July 22, 2018, while she was with her older sister, Letifa Wilson, and a second sister, Tashiya Wilson, trying to return home to Oakland.

Cowell was raised by his grandmother because his mother was in a mental institution for schizophrenia. Saundra Ferriera testified that the behavior of her nephew and Cowell’s mother was very similar: Paranoia, hearing voices, eradicate, destructive.

“Who raised John?” Moore asked Ferriera.

“His grandmother,” Ferriera said. “From the age of four. It was a very good relationship, she was like a mother.”

Nia Wilson
Nia Wilson / Facebook

Cowell’s grandmother passed away while Cowell was incarcerated in prison. Cowell was unable to attend the funeral, and according to his aunt, he could not accept her death. Cowell created a story in his head: Aliens kidnapped, tortured, and planned to kill his grandmother, his aunt testified.

Cowell was locked for a few months in Atascadero mental institution before he was released in May of 2018. The first place Cowell went to sleep at night was his aunt’s house. Ferriera testified, “He was wandering around in a daze. He was paranoid.”

During previous stays at his aunt’s house’s, Cowell would ask to check all of the rooms in the house and turn the lights on because, “he thought there were people there. Aliens or people,” Ferriera said. While staying at her house, Cowell frequently called 911. In June 2014, “he complained about someone out in the field watching,” Ferriera testified. He told police that he had heard gunshots firing at his aunt’s house and believed that his aunt was being held hostage. A SWAT team responded, found no shooter, and Cowell was arrested on a 5150 hold.

When Ferriera became scared of her nephew’s behavior in the summer of 2018, she called his parole officer and said he needed a rehab center that had mental health services. Cowell was heavily abusing drugs, including heroin and methamphetamine, which made his disillusions and erratic behavior worse, according to Ford.

Wilson was stabbed to death at 9:30 p.m. Around 5 p.m. that same day, he had called his aunt. She didn’t answer, so he left voicemails about feeling “scared, paranoid, and wanted to get out of the situation he was in,” Ferriera testified.

Race a theme throughout Cowell’s testimony

While testifying in his own defense last week, Cowell said he stabbed Wilson and her sister because they were “aliens” and “gangsters” who “kidnapped my grandmother.” Wilson’s third sister was unharmed in the attack. He referred to Wilson and her sisters as the “three black females.”

“I’m the victim,” Cowell testified.

Prosecutor Ford told Cowell, “You testified that what you did was the right thing to do, right?”

“Right,” replied Cowell.

“Your plan was to stop these gangsters?” Ford asked.

“To rescue my grandmother from the three females,” Cowell testified. “I was being threatened by three black females working together, threatening to assault my grandmother. They were standing over me. They would not walk away from me. They said they had my grandmother kidnapped.”

As the three Wilson sisters traveled from the Concord BART station to MacArthur station, they never interacted with Cowell. Surveillance video shows Cowell watching the Wilson sisters.

BART surveillance cameras captured the horrifying moment Cowell suddenly slashed Nia and Letifa Wilson’s throats. He fled by running from the BART station while throwing the murder weapon into a construction zone.

Cowell walked for several blocks before he caught a city bus. While riding the bus, Cowell called a black woman on the bus a racial slur. According to Ford, Cowell told the women, “You’re trying to throw something on me, you little n—?”

Moore objected to the evidence being presented in court. At Moore’s request, she went into the judge’s chambers with Ford and the judge. She could be heard yelling through the wall.

Cowell’s testimony contained another seemingly racist moment when he called prosecutor Ford “not the only Mexican with a job.”

Cowell’s testimony on the stand ended shortly after Ford attempted to play the BART surveillance video showing the moment Cowell killed Nia Wilson. Cowell launched into a tirade about his innocence and tried to claim that Ford had already declared him as “not guilty.”

Cowell said, “Didn’t he say I was not guilty? Are you saying I’m not guilty? Or are you taking it back. Everyone heard it. Excuse me, do you remember telling me, ‘not guilty?'”

Cowell then became verbally combative with Ford, saying, “Back the f**k down.”

After the judge ordered deputies to lead Cowell out of the courtroom, Cowell said, “They can’t force me to say s**t if I’m leaving.”

Mother lived in mental institution

Cowell’s mother, Ann Cowell, was unable to raise her son because she lived in mental institutions for long periods of time, family members testified.

Ferriera testified that Ann Cowell was “very paranoid, heard voices, talked to herself, and acted erratically.”

One family member was in tears when she told KRON4 last week, “we’ve doing everything we can to prevent this.”

She said, “They just keep putting him back on the streets. He needs help (and) there is no help out there for the mentally ill. Families try to get them help. They call the police. (Authorities) pick them up, keep them for a short time, and put them back out on the streets. He thought his dad was an alien … so he hit him in the back of the head with a shovel. His dad is lucky he’s alive. It has been going on for a while. His family has reached out, tried to get help, and the police have nowhere to send him because the government closed all of the mental hospitals.”

Nia Wilson
Nia Wilson / Facebook

Cowell is charged with murder and attempted murder.

The attempted murder victim, Letifa Wilson, said Cowell’s courtroom behavior is, “Just an act. He is showing signs of manipulation and reverse psychology. He’s a drug addict, manipulator, and deceitful.”

Letifa Wilson also believes that Cowell has been coached in how to respond to prosecutors. While on the stand, Cowell’s responded to Ford’s questions by stating, “I don’t remember,” dozens of times.

One of Nia Wilson’s high school friends, Jocelyn Gama, told reporters, “I’m tired of always white individuals coming into spaces and using mental health as a card to get away with situations like this. I’m tired of hearing on the news that a white man has killed a black individual and, what they always have to say is, oh it’s mental illness. It’s not OK for John to sit there in court and cuss and say racial slurs. Every time they get to the questions that could find him guilty, he (evades the question).”

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