Cowell is set to be arraigned at 2 p.m. on Wednesday.
A grieving father arrived at court in Oakland before the courtroom was even open. Ansar El Muhammad said it is important to him to be there when John Cowell is arraigned.
VIDEO: 'Remember Her' A tribute to Nia Wilson
John Cowell is accused of stabbing 18-year-old Nia Wilson to death on the BART platform at Oakland's MacArthur station Sunday night. Her sister, Letifah, was also stabbed but survived the attack.
He's in jail and bail has not been set.
"My daughter was everything to me. She was beautiful, so inspirational, she had dreams. I am supposed to be planning her graduation not her funeral. Basically all I want is justice for my daughters," said El Muhammad.
He says Nia was set to graduate Dewey Academy in December.
VIDEO: What we know about deadly stabbing at Oakland's MacArthur BART station
Police say the attack on the Wilson sisters appears to be random. They have not established a motive.
Letifah Wilson told ABC7 News they did not know the man who attacked them and that he came up from behind and stabbed them.
Police looked for Cowell for almost 24 hours and witnesses are now coming forward saying they saw him riding the trains.
Jaunice Reed says she saw him Monday night at the Coliseum Bart Station.
She recognized him as the man BART police were looking for and said she immediately had a reaction to seeing him. "I don't know, he just gave me a feeling in my stomach. I don't know. I don't know. I guess call it intuition," Reed said.
Police say the attack was unprovoked and they haven't figured out a motive.
VIDEO: This is the moment the BART stabbing suspect was arrested
Go here for full coverage on the stabbing at Oakland's MacArthur BART station that took the life of 18-year-old Nia Wilson.
CONTINUING COVERAGE ON DEADLY BART STABBING:
- What we know about deadly stabbing at Oakland's MacArthur BART station
- 'Remember Her' A tribute to Nia Wilson
- Here's how you can help the family of BART stabbing victim Nia Wilson
- Chilling dispatch call describes terrifying fatal MacArthur BART stabbing
- 'He was wiping off his knife': BART stabbing victim recalls horrific attack that killed sister
- Heartbroken father demands justice after daughter stabbed at BART station
- 'Stand down': BART stabbing victim's godfather makes plea to black community
- TIPS: How to stay safe on BART
- Bart releases info on pair of homicides