Editor's note: This story has changed based on new information from police.

The woman shot along with two children in an apartment in Southeast D.C. Monday afternoon has died, and one of the injured juveniles has been charged with her murder, police said in an update late Monday.

Police Chief Cathy Lanier said a 17-year-old boy was in a dispute with his 12-year-old neighbor when he went to the younger boy's apartment with a gun on Tuesday afternoon. Lanier says shots were fired and both boys were wounded, along with the 12-year-old's mother, 31-year-old Tenika Fontanelle.

It's not clear which juvenile has been charged.

The triple shooting occurred about 3:45 p.m. on the 1300 block of Congress Street SE, Lanier said outside the home about a block from the Congress Heights Metro station.

Fontanelle died from her injuries at an area hospital. Her 12-year-old son was shot in the arm, Lanier said.

"Disputes have escalated into violent acts because of the proximity and easy access to an illegal firearm," Mayor Muriel Bowser said on the scene.

The mayor and police chief asked the public to report owners of illegal guns.

"If people will give us the information about the offenders that are carrying these illegal firearms before somebody gets shot, that's how we prevent these things from happening," Lanier said.