D.C. Police have arrested an 18-year-old man from Northeast Washington in connection to the death of 15-year-old John Rufus Evans III, who was fatally stabbed on the platform of the Deanwood Metro station. (WUSA9)

Terogie Wells uprooted her 15-year-old son from his charter school and his District home last month and moved him to Richmond to escape the volatile streets and a group of teens that she said was threatening her oldest child.

But John Rufus Evans III still had obligations in the District. He returned Monday for a juvenile court hearing, and while here, police said, he happened to run into one of the young men with whom he was feuding. Police said they met by chance after getting off different cars of the same Orange Line Metro train at the Deanwood station.

Police said the two recognized each other as rivals, and two witnesses told them that John’s hands “balled up” into fists as he followed the other teenager along the platform and down the escalator to the street. Police said in an arrest affidavit that John told his brother to record whatever happened next and that he did, but accidentally deleted most of it by the time police got to it.

The affidavit quotes witnesses who said that John struck the other teen — 18-year-old Jovante Hall — in the chin and that Hall punched John in the face. John collapsed from a stab wound to the left side of his neck, in an area near the handicap fare gate. Hall was charged Tuesday with second-degree murder while armed. But the prosecutor said later in court that it is unclear who struck the first blow.

“The thing I didn’t want to happen to my son, it happened,” said Wells, 34. “I moved him out because I saw stuff in Northeast — I didn’t like the crowd he was hanging with. I didn’t like the violence.”

Police released these images of a person of interest sought in a fatal stabbing Monday at the Deanwood station. (Courtesy of D.C. Police)

Now, instead of embarking on a new life with her son, Wells is struggling to pay for a funeral and mourning the loss of a child she said was reading at a young age, playing the piano by 7 and, in the eighth grade, painting abstract art while at Richard Wright Public Charter School.

Even with that promise, he had brushes with the law and was due in juvenile court Monday on a charge that he and another teen jumped a person at the Deanwood Metro station and each stole a sneaker, according to documents obtained by The Washington Post. He also had an open theft case.

“He got caught up in a world of violence is that is striking the black-on-black community,” Wells said. “It needs to stop, really.”

She has no idea what the dispute was about but said John’s sister was harassed at Deanwood two weeks ago, with juice bottles thrown at her and threats made against her older brother.

“I just know that boy didn’t like my son,” Wells said.

During Hall’s initial appearance Tuesday in D.C. Superior Court, his attorney, Matthew Davies, argued that his client acted in self-defense and that the charge should be reduced to manslaughter. Hall was dressed in court in Pittsburgh Steelers flannel pajama bottoms and a black T-shirt. His ankles and wrists were shackled.

Prosecutor Christian Natiello argued that a friend of Hall’s who witnessed the incident said that after seeing John in the subway, Hall removed his knife from his pocket, rode down the escalator and walked through the turnstile holding the knife. Natiello said that there were conflicting accounts as to who swung first but that it was clear that John never had a weapon.

“This was excessive force all day long,” Natiello said.

Magistrate Judge Renee Raymond ordered Hall held in the D.C. jail until his next hearing, April 22.

Hall is enrolled at Luke C. Moore High School in Northeast, a spokeswoman confirmed. He has been convicted twice of misdemeanors for assault, for which he served 30 days in jail, and a weapons violation, for which he got a suspended sentence, according to court documents. At the time of the stabbing, he had two pending court cases — unlawful entry stemming from a group fight at the Georgia Avenue-Petworth Metro station, and assault resulting from a dispute inside a store — and was on maximum-level post-trial supervision.

Assistant D.C. Police Chief Peter Newsham, who announced the arrest Tuesday, did not divulge the nature of the dispute, but he said authorities were monitoring social media after friends of the two teens posted warnings of retaliation between rival street crews or groups that frequent the area around Eastern Avenue in Northeast Washington.

Newsham said that neither teen was on police lists of known gang or crew members and that the two had not planned to meet Monday. “It appears they met by chance,” he said.

In announcing Hall’s arrest, police and lawmakers once again confronted questions about safety at Metro stations and made pleas to teenagers to stop fighting and killing over petty disputes and rivalries. Only two weeks ago, another 15-year-old, who was on his way to get a haircut for Easter, was fatally shot on the Deanwood platform when he or his sister inadvertently looked the wrong way at his assailant, according to police.

“Another senseless murder,” Newsham said of the latest killing. [Teenager killed in fatal stabbing at Deanwood Metro station]

D.C. police vowed to step up patrols around the Deanwood station, and Metro Transit Police Chief Ronald A. Pavlik Jr. promised officers during peak times at the stop.

As they seek to prevent further violence, authorities said they were closely watching Twitter and other social media platforms, where messages were posted after the stabbing. “Y’all lives boutta be slim,” one friend of John’s wrote. Another message said: “You Better Hope 12 Getchu First On God You Gon Get Your Due.”

John’s mother said her son was adjusting to life in Richmond, where several relatives live.

“He was actually liking it and had met new friends, and was doing good,” Wells said. “He loved his family, he was intelligent, and he was close to a bunch of brothers and sisters.” Wells said John was also close with his biological father and stepfather.

Dana Hedgpeth, Jennifer Jenkins and Clarence Williams contributed to this report.