- A manhunt was underway for 27-year-old John Cowell. Authorities described him as a white male who is 5 feet, 8 inches tall and weighs 190 pounds. He has short, dark hair, a closely cropped beard and a mustache. He was arrested Monday evening at Pleasant Hill BART station without incident and was booked on assault with a deadly weapon, violating parole and first degree murder.
- BART Police Chief Carlos Rojas says Cowell, who he described "as a violent felon who is currently on parole," was cited for fare evasion on July 18 and his photo was captured by an officer's body camera.
- Surveillance video on the train and at the station's platform showed Cowell had been riding the same car as the sisters, but they did not interact.
- Rojas added, "It looks like it was an unprovoked, unwarranted, vicious attack."
- When he was 18, Cowell's adult criminal record included misdemeanor drug offenses, obstruction of a peace officer and assault. On the assault charge, Cowell was convicted and released on probation.
- When he was 22, Cowell was convicted of battery. Two years later, in 2015, he had another conviction for using drugs.
- In 2016, there were more misdemeanor charges -- this time at the Target store in Contra Costa County. Cowell was caught shoplifting and carrying drug paraphernalia. He was reportedly found with a tear gas canister.
- In May 2016 was Cowell's most serious crime - second degree robbery at Lucky's in El Cerrito. He brandished what appeared to be a handgun at an officer, but it turned out to be a toy gun. He also had a box cutter. Cowell ran from the store and police caught him at the El Cerrito Plaza BART station and he was sentenced to state prison for two years.
- In 2015, a Concord woman filed a restraining order against him. The following year, there was another restraining order. This one from Kaiser Hospital in Richmond, stating he had repeatedly threatened staff members.
- Cowell also has several misdemeanor offenses in Alameda County -- petty thefts, vandalism and drug use.
- He reportedly has tattoos on his body that highlight his ties to Concord. One says "North Concord" and another on his neck reads "925," the area code for Concord.
- Rojas says officers watched several addresses for him in two counties, but he is also listed as homeless.
- Investigators are still trying to determine what led to the attack. Rojas says they have no information it was racially motivated, but they are not discarding that as a possible motive.
- Murder and attempted murder charges have been filed against Cowell.
- Mayor Libby Schaaf says Oakland has no room for hate and the city stands against racial hatred and white supremacy, but reinforced that officials have no evidence that the killing of Wilson was racially motivated.
- Three sisters were on BART, on their way home from a family event, when the suspect attacked as they were exiting one train and transferring to another.
- Nia Wilson, 18, died at the scene. Her sister, 26-year-old Letifah Wilson, was hospitalized with stab wounds to her neck. A third sister was not injured in the attack.
- The sister says they were "blindsided by a maniac" who struck Nia first before attacking Letifah.
- A woman with a stroller reportedly gave Letifah a baby blanket to apply pressure to her sister's neck, but Nia died calling out her sister's name for help.
- Letifah says she told her sister she loved her, "We're gonna get through this, I got you, you're my baby sister."
- The 18-year-old is said to have graduated from Oakland High School. Her sister says she wanted to be a lawyer or do something in criminal justice. Also that she wanted to have a dance studio and her own makeup line.
- The victims' father, Ansar Mohammed, is mourning the loss of his daughter while praying for the recovery of another. He called this a parent's worst nightmare, "That's my baby girl up there. I want justice for my daughter."
- In the meantime, Nia's godfather has asked the African-American community to "stand down" while police investigate."
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
The Associated Press contributed to this report.