Sheriff's homicide detectives were in Lake Los Angeles Saturday investigating a man's death, authorities said.
It happened about 4:30 p.m. in the 40000 block of 176th Street East, Deputy Armando Vierra Jr. of the Sheriff's Information Bureau said.
Investigators said the man attacked two deputies – tackling them both to the ground as they tried to arrest him. A neighbor had to help the deputies so they could place handcuffs on him, they added.
When Lancaster sheriff's deputies arrived, the man initially complied with their commands. But as they went to handcuff him, they say he turned and attacked a deputy -- knocking him to the ground -- and then straddling him.
The other deputy used a Taser, but that had no effect, officials said.
That's when the man attacked the second deputy -- knocking him to the ground and then getting on top of him too, investigators said.
Some witnesses said it looked as though the deputies pummeled the man as he lay on the ground.
Detectives counter that allegation saying that the man was not in handcuffs as he continued to fight the two deputies.
Investigators said only after the man was handcuffed did they notice he began struggling to breath. He then stopped breathing and had no pulse.
Deputies performed CPR, but LA County Fire pronounced the man dead at the scene.
The deputies involved in the arrest suffered minor injuries.
Neighbors told NBC4 that the man who lives at the home used to be pleasant and that the former Marine may have suffered from post-traumatic stress disorder. They added this his behavior in recent weeks had become aggressive and erratic and that he made threats to children and other neighbors.
The man was wanted for several felony criminal threats, sheriff's deputies said.
The victim's name has not been released.
City News Service contributed to this report.