An unarmed man who lost a quarter of his skull after being shot by a Los Angeles police officer notified the city and police department on Wednesday that he plans to sue, claiming the shooting was part of a broad, disturbing pattern in the police force of the nation's second-largest city.

Attorneys for Walter DeLeon, 49, filed the notice of claim in Los Angeles County Superior Court. The notice, a precursor to a lawsuit, accuses police Officer Cairo Palacios of shooting an unarmed DeLeon without warning on June 19 as he was on his regular evening walk to a popular park.

Palacios' attorney, Gary Fullerton, said the shooting was within departmental policy because Palacios was convinced that a towel wrapped around DeLeon's hand was hiding a gun and that he and his partner were in imminent danger.

"He basically forced their hand to deal with him," Fullerton said. "In the matter of a couple seconds they have to make a choice, and the choice is, 'Do I let him shoot me first and then fire?' or 'Do I shoot first and defend myself?'"

Soon after DeLeon was shot, a police spokesman said Palacios and another officer were driving in stop-and-go traffic when they saw DeLeon walk aggressively toward them on a sidewalk.

Police Cmdr. Andrew Smith, a department spokesman, said DeLeon's hands were clasped together and wrapped in a gray cloth, and that the officers believed he had a gun. Smith said DeLeon was shot after ignoring orders to drop the gun.

DeLeon's attorney, Ben Meiselas, said DeLeon had a towel wrapped around his hand to wipe the sweat from his brow on a hot summer day, and that DeLeon had been flagging down the officers for help, though he said his client can't remember why.

"The next thing he was shot, and the next thing he remembers is he was in the hospital," Meiselas said. "This is the most catastrophic of catastrophic injuries and it affects every aspect of life — physical, economic, family. It's a total destruction of self and self-worth, and the only way to rebuild is through this process we're initiating."

DeLeon lost a quarter of his skull, almost all his eyesight and the ability to walk. He still has his memory and most cognitive functions but has trouble speaking.

"My whole life was turned upside-down."

- Walter DeLeon

He spent five months in the hospital, underwent 10 surgeries and is completely dependent on his family's care.

"My whole life was turned upside-down," DeLeon told The Associated Press through tears.

His sister and primary caregiver, Yovanna DeLeon, said her brother has lost everything most people take for granted.

"We get up, we get ourselves dressed and ready to eat, we go about our day ... My brother will never be able to do that again," she said. "If this had been a normal citizen that had done this to Walter, that person would have never seen the light of day."

The DeLeons are seeking unspecified damages. They also want Palacios to face criminal charges and for the department to make changes to ensure no similar shootings ever happen again.

Palacios' attorney said he was still working at the department but is off the streets pending an internal investigation.

Through mid-November, there had been 45 officer-involved shootings in Los Angeles, double the total through the same time period last year. Nineteen of this year's shootings have been fatal, up from 18 deaths in all of 2014 and 26 in 2011.