Authorities have arrested a suspect in the murder last week of a teacher from Kentucky on the campus of The Catholic University of America.

On July 5, 25-year-old Maxwell Emerson was shot and killed on the university’s Washington, D.C., campus.

The D.C. Metropolitan Police Department said in a statement this week that it had made an arrest in the case, apprehending 22-year-old D.C. resident Jaime Maceo and charging him with first-degree murder.

It is unclear if and how Emerson and Maceo knew each other. Emerson was in Washington for a development seminar, his family told media.

Police reportedly identified Maceo from security camera footage showing the altercation that led to Emerson’s death.

Charging documents filed in connection with the arrest reveal that Emerson allegedly texted a family member during the incident and said he was being robbed. Police connected Maceo to the case due to a DNA match from a ski mask left at the scene, according to The Washington Post.

Emerson had been a social studies teacher at Oldham County High School in Buckner, Kentucky. A GoFundMe set up after his death called him a “wise, witty, and hardworking individual who cherished his family deeply.” His obituary said he was born in Lexington, Kentucky, and is survived by his parents, siblings, and extended family.

University President Peter Kilpatrick mourned Emerson’s killing in a statement released after the shooting last week.

“Every human life is made in the image and likeness of God, and we pray for the end of such violence and to help build up a culture that treasures all life,” he said at the time.