She recalled that she and her sisters were returning on BART from a family gathering to honor the life of an aunt who was in the last stages of a battle with cancer.
"The furthest thing from my mind was that a day of celebration would turn into an evening that would traumatize Tashiya and me forever," Wilson said. "I never thought that day would be the last day I saw and held my baby sister."
Her statement touched on widely expressed concerns that Cowell, who is white, was racially motivated in striking out at the Wilson sisters, who are Black.
"Never in a million years would I have thought that something like this would happen to my sisters and me considering we live in a diverse city like Oakland," Wilson said. "You stole my baby sister from her loving family because of your hatred toward Black African American women."
Wilson said she can never forgive Cowell, whom she noted has never expressed remorse, and concluded, "May God have mercy on your soul."
After hearing Wilson and other relatives, Judge Hymer sentenced Cowell to life in prison without the possibility of parole for his murder conviction and a consecutive term of life in prison with the possibility of parole after seven years for his conviction on the attempted murder charge. He was also sentenced to two additional one-year terms for using a deadly weapon in the attack and ordered to pay a total of $10,000 in restitution.
Cowell addressed the court only briefly, to ask Hymer whether his public defender, Christina Moore, would be able to file an appeal within the state's 60-day time limit. Moore confirmed she would be filing a notice of appeal and said she expected another attorney will be assigned to represent Cowell going forward.
One of the issues expected to be a subject of appeal is Hymer's ruling that Cowell was sane at the time he set upon the Wilson sisters at the MacArthur Station.
Hymer made the finding on March 16 after the jury in the case, which had quickly reached a guilty verdict, had spent three days considering the sanity question. The panel was reportedly split 11-1 in favor of finding Cowell sane.
Video from the MacArthur station platform and a nearby BART parking structure clearly showed the attack and its aftermath.
During the one-day hunt for Cowell, former BART Police Chief Carlos Rojas said video of the stabbing, slashing attack "was reminiscent of a prison yard assault, where you have an individual with a sharp object or a shank. And they do their attack so quickly that before anybody can really react, the person takes off running."
Defense attorney Moore conceded at the outset of the trial that Cowell was the killer but argued that he was mentally impaired when he assaulted the Wilsons.
But video evidence and witness testimony established that Cowell appeared to have taken steps to avoid detection after the crime. He directed police officers to the platform and away from himself before fleeing the station, changed clothes immediately after the stabbing and ditched a backpack he was carrying.
A behavioral health clinician who visited with Cowell at the Alameda County Jail in 2018 and 2019 testified that Cowell told him, "I want to look crazy" and that he was optimistic about being found not guilty by reason of insanity.
