A Minneapolis teenager has admitted to three armed carjackings in the Twin Cities, including one when he pulled the trigger on a gun aimed at someone who tried to break up the attack, but the weapon malfunctioned.

Shamir N. Black, 18, pleaded guilty Tuesday in U.S. District Court in St. Paul to one count of carjacking in connection with the violent auto theft in early June outside Tony Jaros bar in northeast Minneapolis.

As part ofa plea agreement, Black also admitted to involvement in two other armed carjackings in Golden Valley this spring. Sentencing for Black has yet to be scheduled. In the meantime, he remains in federal custody without bail in the Sherburne County jail.

According to court documents:

On June 9, Black and an unidentified accomplice approached a 51-year-old employee of the bar in the 2500 block of NE. Marshall Street and demanded her car keys. Black pushed the woman to the ground and hit her on the head with a gun.

A bystander stepped in, but he was also assaulted by Black. During the struggle, Black fired the gun in the bystander's direction, but it did not discharge a bullet.

"He saw [Black] pull the trigger of the firearm, heard the gun fire, and saw the muzzle flash," read the charging document. "However, [the man] was not struck by a bullet."

Black and the accomplice got in the woman's vehicle, and drove it into a brick wall. Other bystanders pulled Black from the driver's seat and put him on the ground. Black and his accomplice fled on foot.

Police found a semiautomatic pistol wrapped in a sweatshirt at the scene that had one round "lodged in the chamber," the charging document read.

Police suspect a car was stolen in a Prior Lake home burglary on the same night the firearm was stolen in a separate home burglary in the same city. Officers recovered the car at Black's home, and he was arrested there on June 24.