Update: John Lee Cowell, the suspect in fatal stabbing, has been arrested. Click here for the latest details. A manhunt is underway for a suspect accused of fatally stabbing an 18-year-old woman and wounding her sister as they stepped off a Bay Area Rapid Transit (BART) train in Oakland, California, late Sunday. John Lee Cowell, 27, was identified by police as the lone suspect Monday after authorities reviewed footage from surveillance cameras at the scene. Investigators have not yet determined a motive for the attack, BART Police Chief Carlos Rojas said in a news conference Monday. Rojas said there was no evidence suggesting the attack was racially motivated, but investigators haven't ruled it out. "In my close to 30 years experience, [it was] probably one of the most vicious attacks I have seen," Rojas said. Police said the suspect was riding in the same car as the victims Sunday and attacked them soon after they exited onto the MacArthur platform. Investigators have recovered evidence at the scene. Cowell, who is white, stands 5 foot, 8 inches tall and weighs 190 pounds, police said. His hair was described as short and dark and he wears a cropped beard and mustache. Authorities said Cowell should be considered dangerous and urged the public to call police if they see him. This undated Facebook photo shows Nia Wilson. Facebook Cowell allegedly struck the women "very rapidly" in what Rojas called an "unprovoked, unwarranted, vicious attack." He said there was no indication that there was a dispute or interaction between Cowell and the victims. Detectives discovered a knife at a construction site near the train station, he said. "It's more 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," he said. Ansar Mohammed, the father of the victims, rushed to the station Sunday evening when he got word of the attack. "I want justice for my daughter. I work at Highland Hospital and I see this every single day," he said, CBS San Francisco reports. "I never imagined myself going through nothing like this. That's my baby girl up there." The woman killed was identified as 18-year-old Nia Wilson. Police said she died at the scene. They said her sister Latifa was rushed to a nearby hospital. "He stabbed my daughter repeatedly," Muhammed said with tears streaming down his cheeks. "This is a parent's worst nightmare." Mayor Libby Schaaf offered her condolences to the victims on Monday. "The senseless and violent stabbing of two young women on a BART train platform last night has shaken our community," Schaaf said in a statement. "Every parent who saw the father of Nia Wilson grieve for his daughter is heartbroken by this horrific act."<doc-sep>OAKLAND (CBS SF) — With tears and smiles, the family of Nia Wilson recalled an 18-year-old Monday who had a love for life and a willingness to help others. UPDATE: BART Police Arrest Suspect In Brutal MacArthur Station Stabbing Wilson was traveling on BART Sunday night with her older sisters — Latifa and Nishiya — when she stopped to help a woman struggling with a stroller exit a train at Oakland’s MacArthur station. It was at that moment that a man pulled out a knife, slashed her across the neck and stabbed her sister, Latifa, before fleeing. Nia’s wound proved to be fatal and the randomness and cruelness of the act was not lost on her family. ALSO READ: “This was a random act, it was cruel. It was a hate crime,” her aunt Brande told KPIX 5 in an exclusive interview. “My niece was out enjoying her day and out of nowhere someone just takes her life.” BART officials announced Monday evening that the suspect in Sunday night’s fatal stabbing that left one young woman dead and a second in the hospital was taken into custody at the Pleasant Hill BART station. Earlier, BART Police Chief Carlos Rojas identified the suspect as a local transient, 27-year-old John Lee Cowell and characterized him as a violent felon currently on parole. Rojas cautioned that investigators have not yet established a motive. “I know there’s been a lot of conversation on social media regarding that, but I don’t have one piece of evidence that would suggest this is race-related,” said Rojas. “But should that be the case, we will pursue the appropriate hate crimes if they’re applicable.” Rojas also said that he was shocked at the violence of the attack. He likened it to a prison-yard stabbing. “As they were transferring at the MacArthur platform, they were approached by and individual with a knife who struck very rapidly,” said the chief. “In my close to 30 years of police experience, it was probably one of the most vicious attacks that I have seen.” ALSO READ: Transient Convicted In Brutal Sexual Assault Of Woman He Met On BART The murder has the family reeling. “My baby was only 18. She was less than 100 pounds soaking wet. This man just came up and did all this to my baby,” her mother, Alicia Greyson said with tears streaming out of eyes. “My baby didn’t deserve this. She hated BART. She was always saying, ‘Mama, I’m scared of BART. '” ALSO READ: BART’s Fleet Of The Future Is Already Spending The Present Getting Repaired Greyson said Nia was a ‘wonderful’ daughter. “She wasn’t in trouble, she’s never been to jail,” the grieving mother said. “She was a cheerleader. She played basketball (at Oakland High)…She had her CPR training…She was so smart and gifted.” The women were returning home from a swimming party and barbecue in Concord when the attack happened, family said. Nia Wilson used her emergency medical training to save a choking relative, her family fondly recalled. “It was my uncle’s funeral,” Greyson said. “My little cousins, their grandmother.. a piece of (chicken) got wedged (in her throat). Everybody tried and tried ( to help her) and then it was taking long and I told Nia to go over and help your cousins…She went over there and assessed the situation. She went behind her and did the Heimlich Maneuver and she started coughing. Saved her life.” Nia Wilson was also excited because she had a job interview all set up for Monday afternoon. “She had a job interview at 2 p.m. today,” Greyson said between sobs. “It was just a little warehouse job, but you know it was a job. She was only 18. She was so happy (about it)…That’s probably why she was out really enjoying herself (Sunday night).” A vigil and rally is being held at the MacArthur BART station in Oakland early Monday evening to remember Nia that had already drawn hundreds of attendees as of 5 p.m.<doc-sep>The stabbing Sunday night on a BART train in Oakland, Calif., that killed an 18-year-old woman and injured her older sister was the third possible homicide on the transit system in five days, but agency officials did not immediately alert the public about the prior two cases. The previous incidents, which occurred Wednesday and Saturday and left two men dead, were disclosed Monday after The Chronicle began asking questions about them. The agency has in the past been criticized for withholding information about crimes on trains and in stations. BART did not immediately respond to requests for comment on why they had not made the other cases public. RELATED: SAPD: Teen shot in South Side home The Chronicle learned of the prior incidents after Sunday’s slaying of teenager Nia Wilson at MacArthur Station. According to BART, 27-year-old John Lee Cowell attacked her and her sister, 26-year-old Lahtifa Wilson, at 9:36 p.m. in a “random” attack as they stepped off a train. Cowell and the women had boarded the train in Concord. Wilson was pronounced dead at the scene, while her sister was rushed to a hospital. Police said they took Cowell into custody at Pleasant Hill BART Station Monday after receiving a tip from a passenger. He was arrested on an Antioch-bound train. BART said the stabbing had no connection to an incident that occurred just after 1 a.m. Saturday, when a man riding BART at Bay Fair Station in San Leandro was punched by an assailant, causing him to fall and fatally strike his head on the cement ground outside the train car. The victim, identified by BART as 47-year-old Don Stevens, a transient, was later pronounced dead at a hospital. The agency on Monday released surveillance images of the suspect, who is wanted for murder. RELATED: SAPD: Gunman at large after killing man who intervened in argument Earlier Monday, the Alameda County coroner’s office declined to provide Stevens’ name, saying BART had asked that the information be withheld from the public. In the potential third homicide on BART, a man who was involved in an altercation Wednesday afternoon at a station in Pleasant Hill was found dead Friday night in his bed at his Pittsburg home, authorities said. The victim was 51-year-old Gerald Bisbee, according to the Contra Costa County coroner’s office. BART said Bisbee was attacked by a 20-year-old man named Abdul Bey, who was arrested and jailed in Martinez. Bisbee, who suffered a bloody lip and small cut to the back of his knee, did not initially seek medical treatment, officials said. He felt bad the next day, though, and visited a hospital, which treated and released him, BART said. On Friday, Bisbee’s loved ones grew concerned that they hadn’t heard from him and asked police to check on his welfare. That’s when he was found dead. Bisbee died from an infection from the cut on his leg, BART said. Michael Cabanatuan and Demian Bulwa are San Francisco Chronicle staff writers. Email: mcabanatuan@sfchronicle.com, dbulwa@sfchronicle.com Twitter: @ctuan @demianbulwa<doc-sep>EMBED >More News Videos Nia Wilson was just 18 years old when she was killed in an unprovoked stabbing at MacArthur BART station in Oakland. Fighting through sorrow, her friends, family, and the community at large are mourning the teenager who brightened the lives of those she knew, and has inspired many who never got the chance. Murder suspect identified in MacArthur stabbing. John Cowell is considered dangerous. Please call 911 if spotted. RIP Nia Wilson. We will bring this suspect to justice. Our thoughts are with the family and friends. Details: https://t.co/DEkTJvJnNe pic.twitter.com/igZU2bdel7 — SFBART (@SFBART) July 23, 2018 EMBED >More News Videos John Cowell is accused of killing 18-year-old Nia Wilson and injuring her sister Letifah Wilson at MacArthur BART. He was arrested Monday afternoon at a different BART station in Pleasant Hill. CONTINUING COVERAGE ON DEADLY BART STABBING: OAKLAND, Calif. (KGO) -- BART police have identified a Bay Area transient as the man responsible for the vicious stabbing murder of 18-year-old Nia Wilson, and the wounding of her older sister Lahtifa Wilson.Officials say that an anonymous tip led to the arrest of the suspected killer, John Lee Cowell, who had been previously cited for not having proof of payment.The community is demanding answers and justice.Nia and her two sisters boarded a BART train in Concord on Sunday night. BART police told ABC7 News the suspect and victims rode the same train to the MacArthur station, and got off around 9:30 p.m.BART PD said the man was unprovoked when he pulled out a knife and attacked the young women. The attack killed Nia. "Everything that we've uncovered up to this point, we see no altercation," BART PD Chief Carlos Rojas said. "We don't have any information that there was any type of dispute. "Chief Rojas described the attack as one of the most vicious he's seen throughout the decades he's spent on the force.Rojas explained BART police officers were on-site, already patrolling MacArthur BART station when the stabbing happened. However, the suspect got away as officers rendered aid to Nia and her sister.Police found the knife used to kill Nia at a nearby construction site.BART PD said surveillance video played a crucial role in this murder investigation, and in identifying the suspect.In the past, BART has been criticized for its use of fake, decoy cameras and its failure to capture other serious crimes.However, BART Board President Robert Raburn told ABC7 News the cameras are now working, and helped provide another look at the suspect.On July 18, officers cited John Lee Cowell for not having a proof of payment. BART PD shared a freeze frame from an officer's body cam.Nia's godfather and a member of the Stop Killing Our Kids organization is hoping evidence will lead to more answers.Daryle Allums said, "We don't know if it's racist, we don't know if this was random. We don't know what it was, but we're asking the African American community to stand down right now. Let's get this information to find out what really happened. "There is growing speculation about whether the attack was a hate crime, and whether the suspect belonged to any white nationalist group.Chief Rojas says the department hasn't found that to be the case. However, commuters aren't convicedLuna Carmen told ABC7 News, "I don't know how divisive everything is getting and all of the racist sentiment here. Seems to be getting worse and it's heartbreaking. "BART police didn't comment on the suspect's mental competency. However, they say he should be considered dangerous. Don't approach Cowell, instead call 911.<doc-sep>
THE SUSPECT: 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. THE VICTIMS: 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." CONTINUING COVERAGE ON DEADLY BART STABBING: OAKLAND, Calif. (KGO) -- Oakland police have arrested a man who they say stabbed two sisters in an apparent random attack at the MacArthur BART station Sunday night. One woman was killed in the attack and her sister was treated for wounds to her neck.