'Up to this point we don't have any information that was race-motivated, but we can't discard it, ' Rojas said.
Bay Area police released new photos that show suspect Cowell John Lee Cowell. Cowell was arrested without any trouble on an Antioch-bound train at the Pleasant Hill/Contra Costa Centre station.
BART police also searched for another homicide suspect who punched a man at the Bay Fair station in San Leandro early Saturday. "It looks like it was an unprovoked, unwarranted, vicious attack", Rojas said.
Police, responding to an anonymous tip from a rider, found suspect John Cowell, 27, riding a BART train Monday night and took him into custody, BART said Monday.
Cowell is considered risky. "As young black women, we shouldn't have to look behind our back you know, we should be living freely like everybody else", said Wilson. One sister boarded the train, while Latifah and Nia waited to let a woman with a baby and a stroller to get off. Moments later, the sisters were both stabbed in the neck.
He then attacked and wounded her.
Brooks also told Indybay that the attack on the Wilson sisters was just another example of rising violence experience by African American girls in Oakland every single day. "This man just came up and did all this to my baby", her mother, Alicia Greyson said with tears streaming out of eyes.
Wilson said she told her sister she loved her.
It all began Sunday night when Nia Wilson and her sisters did something they normally didn't do.
Mass protests have spread across Oakland demanding justice for the murdered teen.
Writer and civil rights activist Shaun King shared the story on Twitter Monday, urging people to help find Cowell. They believe they've found the knife he used in the stabbing at "an adjacent construction site".
Police still don't have a motive.
Surveillance footage showed Cowell fleeing the station through a parking lot and stripping off his clothes there.
After the attack, surveillance cameras captured the attacker shedding his clothes in a nearby Bart vehicle park.
"Up to this point, we do not have any information that suggests it is race-motivated, but we can not discount it at this time", he said during a press conference on Monday.
Cowell was seen on surveillance video stabbing Wilson and her sister before running from the scene, according to documents provided by the Alameda County District Attorney's Office. Police say he is a transient and a violent felon who is now on parole.
Items comprising the makeshift memorial were placed there there to commemorate 18-year-old Nia Wilson, fatally stabbed Sunday night at the station Sunday night by a stranger. Lahtifa Wilson survived the attack.
Nia, Tashiya and their family DESERVE justice! She says he's lived in and out of this Concord home and over the years has been in trouble with the law. Rojas said the quickness of the "prison-yard" style assault allowed the suspect to elude police. Nia's wound proved to be fatal while her sister was being treated at a local hospital.
Alicia Greyson, the victim's mother, described her as a "wonderful" daughter who had been a cheerleader and basketball player at the Oakland high school.
Wilson's death is the third linked to the Bay Area rail in less than a week.