"This was a very tragic incident, but we have no legal basis for a criminal charge," said Dan Donohoe, a spokesman for the King County Prosecutor's office.
The victim, Christopher Harris, has been in critical condition ever since he was tackled by the deputy, who thought Harris was a suspect in a knife attack on May 10. Harris, 29, suffered multiple skull fractures.
In the days after the incident, Sgt. John Urquhart with the King County Sheriff's Department said Dep. Matthew Paul, 26, tackled Harris because he ran when deputies ordered him to stop.
Witnesses said the incident began when several men, some covered in blood, ran into a convenience store where Harris had been shopping. Deputies chasing down the suspect were mistakenly told by witnesses that Harris was the man they wanted. Harris had not been in the fight, but he ran.
Harris' family attorney argued anyone else would have reacted in a similar fashion.
"If you see a 275-pound man and another man both in paramilitary outfits, yelling at you from half a block away down a dark alley and they don't identify themselves as policeman but yell at you, 'Hey!' I think that's good cause to run," attorney Sim Osborn said in May.
Urquhart, who later released surveillance video of the episode, said a preliminary investigation by the sheriff's office showed there was probable cause to arrest Harris because he fled from two deputies who repeatedly identified themselves as police.
The video shows the end of the chase as moviegoers are exiting from the Cinerama theater, about 2½ blocks from where the chase began.
Harris comes into view, makes a slight turn and slows down as Paul gives him a fierce shove, knocking him off his feet. Harris' head slams into the base of a tiled wall outside the movie house.
Two witnesses say Harris seemed to be stopping and said, "I don't have anything, I didn't steal anything," just before he was hit by Paul, who weighs about 270 pounds, about 100 pounds more than Harris, family lawyer Simeon Osborn said.
But Donohoe said since Christopher Harris was identified by witnesses to officers as a suspect in a violent crime, "The law provides that an officer 'shall not be held criminally liable for using force without malice and with a good faith belief that such act is justifiable.'
"He ran for several blocks after he was told to stop by uniformed officers. As the deputy caught up to him, the deputy used a standard take down procedure. As a result, no criminal charge can be filed."
Urquhart said another deputy, 28-year-old Joseph Eshom, was involved in the foot chase. Eshom, who has been with the department for about two years, transferred from the Phoenix Police Department.
Both Paul and Eshom are assigned to the graveyard shift of Metro Transit Police duty to ensure the safety of drivers and passengers on overnight bus routes. Eshom has returned to work. Paul was on paid leave administrative leave.
"This is a huge tragedy certainly for Christopher Harris and his family, but for our deputy as well. This looks to be nothing more than an accident. Certainly the deputy didn't plan on injuring Christopher, as it turned out," Urquhart said in May.