Nieto's parents filed a federal wrongful death lawsuit against the city in August, which is still pending.

The Nieto family refused to meet with Gascón today, according to a statement released this afternoon from supporters. The statement said the district attorney's decision was predictable, and that the family's lawsuit will proceed.

"We stand with the Nieto Family by turning our backs on the criminal justice system too,” the statement said.

The DA's Investigation

According to Gascon's letter, several people walking in the park noticed Nieto had what they thought was a gun and were frightened by his behavior. Family and supporters have said he carried a Taser for his job.

One man told investigators Nieto pointed a Taser at his dog, shouted profanity, and aggressively challenged him. The witness attempted to notify police just after 7 p.m. via SFPD's non-emergency phone number, but was unsuccessful, the letter says.

Two of three separate witnesses who called 911 at 7:09 p.m. reported seeing a man with a holstered gun, shadow boxing . (Listen to SFPD radio scanner audio of the incident.)

SFPD Sgt. Jason Sawyer (now a lieutenant) and Officer Richard Schiff responded to the call and encountered Nieto in the park sometime after 7:12 p.m. They stopped their patrol car 25 to 30 yards in front of Nieto, exited with their guns drawn and commanded him to show his hands.

Nieto pulled a weapon both officers believed to be a firearm, the letter says.

According to the district attorney:

Both officers discharged their firearms at Mr. Nieto. After a number of shots were fired, Mr. Nieto continued standing with his weapon still pointing at the officers. Both officers continued firing towards Mr. Nieto, at which point he dropped to his knees and then laid down flat on the ground in a prone position with his head up, his arms outstretched in front of him, and still pointing his weapon at the officers. Officer Schiff thought Mr. Nieto might have taken this position as a tactical maneuver to make his body a smaller target. Officer Schiff then, for the first time, saw the red light coming from Mr. Nieto’s weapon and thought it might be a laser sight. Both officers believed Mr. Nieto was still trying to fire back at them and continued to fire at Mr. Nieto.

Officers Roger Morse and Nathan Chew arrived at the scene in a separate patrol car shortly after the first shots were fired and began shooting at Nieto as he lay on his stomach.

"All four officers continued firing until Mr. Nieto's head and weapon went down and Sergeant Sawyer yelled for officers to cease fire," the letter says. The DA found that the four officers fired a total of 59 rounds at Nieto.

Analysis of Nieto's Taser showed it was fired approximately five seconds after Sawyer and Schiff began shooting.

The San Francisco Medical Examiner previously found Nieto had been shot 14 or 15 times. The medical examiner's report also included a description of Nieto's medical records obtained from San Francisco General Hospital, which included "a history of aggressive and bizarre behavior and auditory hallucinations, and a clinical history of psychosis" exacerbated by his failure to take medications, the district attorney's letter says.

Nieto was twice taken into custody by SFPD in 2011 for a 72-hour mental health evaluation, according to the DA. The estranged husband of Nieto's friend also reported Nieto had shot him with a Taser just a few weeks before the Bernal Heights shooting. Nieto and the man filed dueling restraining orders against each other.



"The belief of each officer that Mr. Nieto’s weapon was a firearm was clearly reasonable," Gascón concluded. "Under these facts, the use of deadly force was justified. It is, therefore, our conclusion that Sergeant Sawyer, Officer Schiff, Officer Morse and Officer Chew acted lawfully."

Read district attorney's letter below: