Four Crystal police officers justifiably "feared for their lives" when they shot and wounded an armed 18-year-old in a park last spring, the Hennepin County attorney's office said Thursday.

Police shot Khaleel Thompson shortly after 9 a.m. on May 24 in Bassett Creek Park. Thompson was wounded in the head and on the right side. He remained hospitalized for more than a month until his release July 5.

"This was a justified use of deadly force by the officers," County Attorney Mike Freeman said in a statement, adding that no charges will be filed against the officers.

Freeman and two senior prosecutors reached their conclusion because Thompson put both of his hands on what investigators say was a BB gun disguised as a more dangerous firearm. He then aimed it directly at one of the officers.

"The officers not only pleaded with Mr. Thompson to drop his weapon but used a nonlethal beanbag rifle first in an effort to get him to drop the gun," Freeman said. "All those measures failed and ultimately the officers feared for their lives and fired numerous shots."

Officers found a bottle of red nail polish near Thompson. "The polish was used to cover the orange tip of the gun so police would think it was a real gun, rather than a BB gun," read a county attorney's office synopsis of the investigation.

The state Bureau of Criminal Apprehension's investigation into the shooting revealed that Thompson struggled with depression and paranoid schizophrenia, had numerous perilous encounters with police over the past two years and expressed wanting officers to kill him.

Naomi Thompson, Khaleel's mother, said at a City Council meeting two weeks after the May shooting that her son's friends called police the night before the shooting and "made it clear he was mentally ill."

The friends told police Thompson was talking about wanting to die, but instead of helping him, the officers just left. "Why did they leave?" she asked. "Why did they not help him? Why did they not take him in?" The Star Tribune left messages with her seeking her response to the officers being cleared.

Freeman's decision to take the case himself continues his office's practice of bypassing the option of having a grand jury weigh charges in officer-involved shootings, which began with review of the killing of Jamar Clark by Minneapolis police in November 2015. The officers were cleared in the case as well.

Freeman's office made public the entire case file, including video from the officers' interactions with Thompson. Dashcam video reveals one officer yelling "Drop the gun!" repeatedly. Two other officers arrive and yell the same command several times.

After Thompson was shot, one officer is heard saying, "He kept pointing it at me. … He kept pointing it at us, repeatedly."

Earlier incidents

The BCA investigation detailed his earlier tense encounters with police as well as what unfolded in the moments leading up to and including the shooting in Crystal.

In October 2015, Thompson was on a St. Louis Park street with an ax and told police that people were going to die. The officers persuaded him to drop the ax and rushed him to the hospital. They later learned Thompson made the 911 call and hoped police would kill him.

In June and November 2016, police took him to a hospital because he was depressed and threatening suicide. In each case, doctors said Thompson wanted "death by police."

In January, St. Louis Park police were called and Thompson was outside a house, with a knife, and threatened suicide. Again, police took him to the hospital. He told doctors he was angry that police would not shoot him and said that next time, "maybe I'll just get a gun."

Two days before the shooting in the Crystal park, Thompson returned from treatment in California and stayed with a friend in Golden Valley. The next day, police were called to the house because his friends reported Thompson was talking about suicide. Thompson assured police he was fine, and they left.

The friend's father directed Thompson to leave the house. Thompson left on the morning of the shooting and took his friend's airsoft BB gun.

Showdown in park

Shortly before 9 a.m., Crystal police officer Bryan Elfstrom responded to the call of a man with a handgun.

Elfstrom saw a man on the hill with a handgun in his right hand. He ordered Thompson several times to drop the gun, while the officer drew his handgun. Thompson, about 100 feet from the officer, responded, "not today" or "I can't today."

Officers Mason Barland and Txheng Vang soon arrived. Thompson pointed the weapon in their direction, and Barland fired two beanbags. One bag took Thompson to his knees. Officer Kathleen Gomez, grabbed her rifle and shouted to Thompson, "What are you doing?" and "What are you thinking?"

Thompson rose from his knees and aimed the gun toward Barland. Elfstrom immediately shot at least a dozen rounds. The other officers also opened fire, and Thompson went down.

State trooper Sara Evans joined Gomez and Elfstrom near Thompson. Evans noticed the gun under the teen's left leg and grabbed it, along with a knife and the nail polish.

Police also found a cellphone near the scene, and it showed a six-minute 911 call to police beginning at 8:53 a.m. Police later had friends listen to the call, and they said it was Thompson's voice.