18-year-old Nia Wilson and her sister, 26-year-old Latifah Wilson, were allegedly stabbed by 27-year-old John Lee Cowell on Sunday at 9:36 p.m. at the MacArthur BART station, according to a BART press release issued Monday.

The sisters were transferring trains at the MacArthur platform when Cowell, a felon on parole, allegedly assaulted the girls, according to the press release. Nia Wilson was declared dead at the scene and Latifah Wilson was taken to a nearby hospital.

“It was, in my close to 30 years of police experience, probably one of the most vicious attacks that I’ve seen,” said BART Police Chief Carlos Rojas at a press conference before taking the suspect into custody.

Cowell fled the scene through the BART parking lot, taking off his clothes, and disposed of the alleged weapon, which was found at an adjacent construction site, Rojas said in the press conference.

After receiving an anonymous tip from a BART rider, authorities arrested Cowell aboard an Antioch-bound train at the Pleasant Hill/Contra Costa Centre station Monday night, the press release said.

“We don’t know if this is racist. We don’t know if it was random. We don’t know what it is,” said Daryle Allums, a member of the group Stop Killing Our Children and godfather of Nia Wilson, at the press conference. “We are asking the African American community to stand down right now. Let’s get this information to find out what really happened.”

The MacArthur stabbing incident was the third suspected homicide on BART in the past week, according to the press release. On Saturday at 1:20 a.m., 47-year-old Don Stevens received a hit to the head by another man at the Bay Fair BART station. Stevens was transferred to the hospital but later declared brain-dead.

According to the press release, the suspect is described as a Black man with shoulder-length dreadlocks, a dark complexion, and a height of between 5 feet 8 inches and 5 feet 10 inches.

The third incident occurred July 18 when 51-year-old Gerald Bisbee was allegedly assaulted by 20-year-old Abdul Bey at the Pleasant Hill/Contra Costa Centre station, the press release said. Bey was arrested shortly after the attack and remains in custody.

Bisbee went to the hospital the next day after receiving a bloody lip and a small cut on the back of his knee, the press release said. After being released, he was found dead in his bed on Friday from an infection from the cut on his knee.

Rojas said in a press conference that no patterns or similarities have been identified among the three incidents.

In 2018, there have been 222 violent crimes on BART — a 2 percent increase from 2017, according to crime statistics on BART’s website.

BART has been trying “really hard” to reassure riders that BART is safe and that the organization is working its hardest to make improvements, Rojas said at the press conference.

“These incidents are occurring in our communities and bleeding into our stations,” Rojas said at the press conference. “So we’re dealing with the same thing that any community in the Bay Area, or throughout California, is dealing with.”