District Attorney Brian Mason declared three Adams County deputies justified in fatally shooting a man who had killed his ex-wife’s parents and approached them with a knife.

The 17th Judicial District Attorney’s Office will not file criminal charges against Deputies Zackery Alvarado, Nicolas Kijowski and Kyle Franklin after deciding the use of deadly force was appropriate.

The shooting happened early June 6, 2025, when deputies responded to a 911 call from Robert Santistevan, who told dispatchers he had killed his ex-wife’s parents in their house.

Santistevan told the dispatcher that responding officers would “have to kill him upon their arrival.”

Four Adams County deputies responded, noting a pickup truck had been driven into the garage door, according to the decision letter.

Santistevan came out of the house with blood on his arms and something in his hand, deputies said. They called him on his phone and he went back inside, telling them again on the phone that they would have to kill him.

He came back out of the house with a knife in his hand and walked toward the deputies, who told him to drop the knife. He ignored the commands and told the deputies to shoot him, according to the decision letter.

Two of the deputies shot him with nonlethal foam bullets and a taser, but he got up and kept walking toward them.

Alvarado, Kijowski and Franklin then all shot him with their guns. He was taken to a local hospital for treatment, where he died from his injuries.

Deputies found two people dead in the basement of the house.

Santistevan had a blood-alcohol level of 0.138 at the time of death, an autopsy showed.

Under Colorado law, a law enforcement officer can use deadly physical force when it is “necessary and reasonable.”

The decision letter states that the deputies were justified in shooting Santistevan because he acted aggressively, ignored commands, had already killed two people and withstood less lethal means of controlling him.