In a joint statement from the U.S. attorney's office in Boise, Idaho, and prosecutors in Valley County -- where DiMaggio was killed -- officials said the agents would not face prosecution or further investigation at either the federal or state level.
That determination, officials said, was based on evidence from the rugged mountain campsite where DiMaggio and Anderson were found and an FBI probe into the shooting, which included an autopsy report on DiMaggio and an interview with the teenager after she was rescued.
The search for Anderson began Aug. 4, when the bodies of her mother, Christina, and 8-year-old brother, Ethan, were found in DiMaggio's burning home in eastern San Diego County. Authorities said DiMaggio, a family friend, killed the two before kidnapping the girl.
The manhunt stretched across the western United States for days, until a group of horseback riders spotted DiMaggio and Anderson in a stretch of remote, rugged wilderness about 75 miles north of Boise. DiMaggio's car was found nearby, hidden under logs and thick brush.
Federal, state and local authorities swarmed the area and, six days after the search began, a law enforcement plane identified DiMaggio and Anderson at their campsite near Morehead Lake. An FBI hostage rescue team was dropped in from a distance to avoid alerting DiMaggio, and hiked two hours in the steep terrain to reach the site.
The agents moved in when DiMaggio and Anderson separated.
"When several agents got within approximately 100 yards of the subject, DiMaggio fired two rifle shots," prosecutors said in the statement released Wednesday. "Two agents, who could see DiMaggio and were directly within his firing line, believed DiMaggio was shooting toward them. They two agents returned fire, striking DiMaggio several times."
A third agent found and safely rescued Anderson, prosecutors said.
Valley County coroner Nathan Hess said an autopsy report showed DiMaggio was shot six times in the head, chest and extremities.
The rescue, prosecutors said, was captured on infrared video recorded from the law enforcement plane that stayed above the campsite. That video showed an "overview of the action of the individuals involved and the heat from the shots that were fired."