D.C. police have arrested and charged 18-year-old Jovante Hall with second-degree murder after he allegedly stabbed 15-year-old John Rufus Evans III to death at the Deanwood Metro station on Monday.

In announcing Hall’s arrest on Tuesday morning, Metropolitan Police Department Assistant Chief Peter Newsham said during a press conference that information from residents was essential in apprehending Hall last night, following the release of survillence photos depicting a person of interest. Newsham said police believe Hall and Evans had had a dispute before the stabbing. He added that a Metro Transit Police Department officer performed CPR on Evans before he was taken to a hospital, where he was pronounced.

“I want to underscore the fact that there are cameras all over our system,” Mayor Muriel Bowser said of Metro. “I also want to emphasize that we have worked with Metro to ensure we have an increased presence throughout our system.”

Officials also announced that the Deanwood station—where 15-year-old Davonte Washington was killed in front of his relatives in late March—would get “around-the-clock” MTPD presence starting immediately:

Metro Transit Police will have around-the-clock presence at Deanwood Metro Station, effective immediately. pic.twitter.com/IYyFlejcHB

— Public Safety in DC (@SafeDC) April 12, 2016

According to NBC4, Evans had been in D.C. for a scheduled court appearance on Monday, though he lived in Richmond with his mother. The Post reports that Evans had attended Richard Wright Public Charter School in Southeast.

“I was sick, and I couldn’t take him to his appointment,” Terogie Wells, Hall’s mother, told NBC4. “He came up, hugged and kissed me, and said he’d be back. I just wish I would have went with him.”

An MPD report from last month shows that an 18-year-old named Jovante Hall was arrested shortly before 4 a.m. on March 3 on charges of simple assault and unlawful entry at 4200 Nannie Helen Burroughs Avenue NE, the site of a gas station.

Photo by Darrow Montgomery