An 18-year-old Washington man pleaded guilty Monday in a burglary in upper Northwest Washington in which an 81-year-old woman was knocked unconscious and left with broken teeth, authorities said.

Tyran Mcelrath pleaded guilty to first-degree burglary and aggravated assault in the break-in last year at a house in the 3500 block of McKinley Street NW, according to the U.S. attorney’s office for the District.

After breaking in through a basement window the morning of Nov. 7, Mcelrath took tools from the basement and then rifled through cabinets on the main floor and took change from the woman’s purse, prosecutors said. They said he carried an Apple computer outside and hid it in bushes at the bottom of the front steps.

After the woman discovered the break-in, she walked toward the front door and “politely asked Mcelrath to leave,” prosecutors said. “He then punched her repeatedly in the face” until she lost consciousness, they said.

The attack left her disoriented, with bruises and damaged teeth, according to prosecutors.

They said Global Positioning System records showed Mcelrath in the home when the break-in occurred. GPS information located him the next day in Southeast Washington, they said.

Courts in the District may require the wearing of such devices as a condition of release pending trial.

It was previously reported, citing information provided by officials familiar with the case, that Mcelrath had a juvenile record involving similar offenses. However, authorities have not discussed that publicly.

According to the prosecutors, when located Nov. 8, Mcelrath was wearing a mask “that was the same one” as that described by the victim.

In addition, prosecutors said, surveillance video from Metro showed him going to and from the crime scene. The house is on a bus route.

Mcelrath expressed remorse after his arrest, authorities said.