Authorities are countering accusations made this week about their actions during a standoff last year that left a man and his 5-year-old son dead.

The man's widow, Chanell Santistevan, alleged in a lawsuit filed Tuesday in U.S. District Court that a single bullet fired from a Denver SWAT team member's rifle killed her husband and son at a Denver apartment Aug. 7, 2006.

Denver Police Chief Gerry Whitman and a medical examiner said Thursday that the evidence showed that Elias Santistevan shot his son and then himself.

"I'm not surprised by the lawsuit," Whitman said. "They may have an opinion based on some of the facts, but in reality the officers' conduct over that 12-hour period, and especially at the scene, was commendable."

The deadly chain of events began on a Sunday, when Santistevan, 22, assaulted his wife at an automotive sound system shop where he worked. After the assault, he became worried that he would have to go back to prison to complete a five- year sentence for robbery.

By 8 a.m. the next day, Santistevan was holding his son, Deion, and three other people hostage at the Denver apartment of an acquaintance. When the first officers arrived, Santistevan fired eight rounds at them with a .40-caliber semiautomatic handgun. One officer fired a blast from a shotgun in return, Whitman said.

By 9 a.m., SWAT team members were in position, but they did not fire a single shot during the rest of the standoff, Whitman said.

The chief said he gave the team permission to use explosives to blow open the apartment door and use flash grenades about 1:30 p.m., after a negotiator heard a shot during a phone call with the suspect.

"The chain of events is we heard a round, we breached the door and by the time we forced our way into the bathroom, they were already shot," Whitman said.

A day after the shootings, Chanell Santistevan told the Rocky Mountain News that her husband killed their son after police tried to end the standoff by force.

Denver Medical Examiner Dr. J.W. Wahe, who conducted the autopsies, said that Santistevan killed himself with the .40-caliber handgun moments after shooting his son with the same weapon.