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Update: The suspect in the stabbing that left Nia Wilson dead has been arrested by BART Police at the Pleasant Hill station. Details are here.

OAKLAND — The manhunt for a Concord man identified as a primary suspect in a double stabbing on a BART platform that killed an 18-year-old Oakland woman and critically wounded her sister continued Monday as authorities released his mug shot and images of him.

John Lee Cowell, 27, is considered dangerous, and authorities urged anyone who sees him to call 911 immediately. He is suspected of following Nia Wilson, 18, and her sister off a train onto the platform at the MacArthur Station and stabbing both of them.

Wilson died at the scene. Her sister, whom authorities identified as Latifa Wilson, remained hospitalized Monday with critical injuries, police said.

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

Nia Wilson’s godfather, Daryle Allums, called for the community to help bring justice to the family but not react violently.

“They didn’t ask to be stabbed, those are baby girls,” Allums said Monday. “We don’t know if it’s racist, we don’t know if it’s random.”

The stabbing death marked the second in two days on a BART train and third in five days. BART said a man punched at the Bay Fair station early Saturday morning hit his head on the cement and died Sunday at a hospital. Police also were investigating the death of a man assaulted at the Pleasant Hill station on July 18.

Police did not put out a statement regarding either the Bay Fair or Pleasant Hill incidents until Monday, when they released Cowell’s images. BART officials did not immediately address the delay in reporting the incidents.

Cowell, a transient based in Concord, has a history of arrests, including for assault with a deadly weapon and robbery. In 2016, a Richmond hospital sought a restraining order against him for allegedly calling a worker a “crack-headed (expletive)” and constantly threatening to kill her.

He also had prior arrests in Alameda County for one case involving petty theft and another involving misdemeanor vandalism and misdemeanor possession of a controlled substance.

Authorities said that Wilson and her sister both boarded a train at the Concord station, as did Cowell. All three then exited at the MacArthur transfer station to wait for a Warm Springs train. The stabbing happened on the platform of the station, authorities said.

At a Monday news conference, BART Police Chief Carlos Rojas said the stabbing was similar to a “prison yard assault” and happened quickly, which allowed the suspect to escape. It also was captured on video “very clearly,” according to a source. Rojas said that video will not be released.

Police found a knife used in the stabbing at a nearby construction site, Rojas said. A backpack left behind at the crime scene helped police identify Cowell as the suspect.

It’s “one of the most vicious attacks I’ve ever seen,” Rojas said.

Cowell had just finished completing a two-year prison sentence for a robbery conviction. It stemmed from a May 2016 incident, when he displayed a box cutter and replica handgun during an “encounter” with a loss prevention officer at a Lucky’s in El Cerrito, authorities said.

In 2015 and 2016, separate restraining orders were issued against Cowell, one alleging that he entered his family’s home several times without permission while “high on drugs,” prompting a family member to call police.

The other restraining order, issued in July 2016, alleges Cowell began harassing a woman who worked at the Kaiser Permanente hospital in Richmond. Cowell, according to the restraining order, began swearing at the woman and demanding she find his backpack.

“(Cowell) then turned to a co-worker who was also working at the reception desk. He stated to her that she ‘better not be friends with’ me or she would get ‘shot in the face also,'” the woman wrote in court records. “Every time he comes to the department when I am working, he is verbally abusive and threatens my life.”

The situation was serious enough that Kaiser asked for the restraining order request to be expedited, writing they were afraid Cowell would carry out his threats if an order wasn’t issued right away.

In Alameda County, warrants for Cowell were issued when he failed to show to court for hearings involving his arrests on suspicion of petty theft in one incident and misdemeanor vandalism and possessing a controlled substance in the other. Cowell was in jail at the time in Contra Costa County.

In the petty theft case, police arrested Cowell on suspicion of stealing underwear from Whole Foods in Dublin.

Cowell is a Caucasian male who is 5 feet, 8 inches tall and weighs 190 pounds, authorities said. He has short, dark hair, a closely cropped beard and a mustache.

He has scared acquaintances in the past. Carol Kincaid, a neighbor who said she has known Cowell since he was in diapers, was informed of Cowell’s suspected involvement in the stabbings by a reporter Monday. She said she wasn’t surprised.

“I think he would absolutely kill somebody if he had something against someone,” Kincaid said. “He’s no good at all.”

Kincaid remembered one story about Cowell from a few years ago where he went to a nearby Burger King with his grandmother and ordered food through the drive-through window. The clerk upset him, so after returning home, Cowell grabbed a brick, walked back to the restaurant and threw it through the window.

Kincaid said Cowell recently returned to the neighborhood a few months ago after serving time and was living with an aunt across the street. She said Cowell asked her for a ride to BART about a month ago, and that she and her husband reluctantly agreed. She said Cowell acted odd the entire trip, the last time she saw him.

“As he got older and older and out of school, he was always in trouble,” Kincaid said. “… Everybody was afraid of him. He didn’t care what he did to anybody. He’s not any guy you want to be around.”

No one answered the door bell Monday afternoon at Cowell’s childhood home, a grey Ranch-style house with brick accents. Two large trucks were parked in the driveway, next to a well-manicured lawn, a decorative well and a sign that read: “Welcome Y’All.”

Other neighbors in the small cul-de-sac that sits at the end of a long driveway from Concord Boulevard and a vet hospital, had vague memories of Cowell. Some occasionally saw him smoking on a bench next to an adjacent dirt yard with out buildings, stored boats and tractors.

On Monday morning, a Contra Costa County sheriff deputy knocked on the doors and showed the residents a photo of Cowell and asked if they had see him around recently.

Shortly after the stabbing around 9:35 p.m., passengers flagged down officers at the Oakland station and they found the two women. Wilson died at the scene. The station was closed overnight while investigators processed the scene on the platform, BART spokesman Jim Allison said. The station reopened at 4 a.m. Monday.

Wilson’s death sent Twitter into a rage. Around 11:45 a.m., it was briefly the top-trending story on the site. Many people reacting to the stabbing demanded security footage immediately.

#NiaWilson needs to be the #1 trending topic in America and a manhunt needs to be underway for her killer. She was a kid. The 25-30 year old white man who murdered her and critically injured her sister walked up to them and began slashing them with a knife. (via @ShaunKing) pic.twitter.com/hw3sh0CxtB — Arturo Tha Cuban (@ExtremeArturo) July 23, 2018

A post by @veganwaterpls spoke for many of them, saying, “Nia Wilson was murdered last night at MacArthur @SFBART station in Oakland, CA by a white male still at large. Where is the security footage? Where are his photos & why aren’t they being plastered everywhere? What is BART going to do?”

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New downtown San Jose transit village comes into view Said @extremearturo: “#NiaWilson needs to be the # 1 trending topic in America and a manhunt needs to be underway for her killer. She was a kid.”

While BART is the lead agency investigating, Mayor Libby Schaaf said Oakland police are providing support and resources to identify and arrest the man responsible for the attack.

“We all mourn in this moment and we will all work together to bring justice for Nia, her sister and their family,” Schaaf said.

Check back for updates.

Contact George Kelly at 408-859-5180.