Updated

A police officer shot and killed a convenience store worker who plowed into him on a sidewalk while frantically fleeing an armed robbery early Friday, a sudden encounter that the police department called a tragic accident.

Three men taken into custody at the shop after the shooting were charged with murder, robbery and weapons possession, prosecutors said.

Dramatic security video released by police shows the uniformed officer, his gun drawn, positioned outside the Bronx shop's front door moments after a 911 call. In a flash, the store manager rushes out the door. Closely behind with his head down is Renaldo Cuevas, who runs full speed into the officer, sending both men tumbling to the sidewalk.

A pool of blood appears to form on the ground the instant Cuevas lands on his back. The officer is kneeling and pointing his semiautomatic at Cuevas when the video clip ends.

Investigators believe the impact of Cuevas running into the officer caused him to fire one round, striking the 20-year-old victim in the left shoulder, police Commissioner Raymond Kelly said at a news conference. Cuevas died later at a hospital.

Though the death appeared to be an accident, the officer was placed on desk duty pending an investigation, a routine practice for all New York Police Department shootings. Officials refused to release the name of the seven-year veteran of the police force.

There was no sign that the shooter and other officers at the scene mishandled the situation, Kelly said.

"The tragedy here of course was that Mr. Cuevas was shot, but I see nothing wrong with the procedure," he said.

Added Kelly: "We want to extend our deepest condolences to the family of Mr. Cuevas for their loss."

The fatal police shooting, one of two in the city on Friday, came two weeks after two police officers wounded nine people by shooting a total of 16 rounds at an armed murder suspect, leaving him dead in the shadow of the Empire State Building. The bystanders all were struck by police gunfire, ricochets and fragments.

In the second police shooting Friday, officers were summoned to contend with a man holding a knife to his neck in a Queens home. Officers repeatedly ordered the man to drop the knife, but he refused and began approaching an officer while holding it in the air, police said. The officer fired once and hit the man, who was taken to a hospital and died Friday evening, police said.

Felix Mora, the manager of the Bronx convenience store that was robbed earlier Friday, told reporters he was closing up with Cuevas, the shop owner's nephew, well after midnight when the three men barged in and one pointed a gun at them. One warned, "Don't move. I will kill your son if you move," he said, explaining that they thought Cuevas was his son.

"I was so scared. I was just praying for the cops to come," the 43-year-old Mora said.

A passer-by called police at about 2 a.m. to report the holdup. When officers arrived, they looked through a window and saw Mora and Cuevas being held hostage at gunpoint, police said.

Another security video shows a masked gunman hitting the manager with a pistol as he pushes both men to the floor. It also shows one of the bandits peering out the window, then, apparently realizing police were there, bolting to the back of the store, giving the victims a chance to slip away.

Mora told investigators he had heard one of the men yell in Spanish, "Policia! Policia! Policia!" meaning, "Police! Police! Police!"

After the shooting, one of the robbers quickly surrendered, police said. The two others retreated to the basement and remained inside until police threatened to send in a dog, Kelly said.

One of the men emerged around 5 a.m., claiming to be a victim. Police found the second man tied up inside as part of the ruse, police said.

Police said they found a .32-caliber handgun, which was never loaded, and the robbers' backpack, which contained $718 in cash, cigarettes and scratch-off lottery tickets.

Across the street from the bodega, Cuevas' friends set up candles and put up hand-drawn posters on the wall that included messages reading, "RIP Reynaldo" and "We want justice."

Mora called Cuevas "a good kid, a hardworking kid, a happy kid."