LOS ANGELES (CBSLA.com) — Criminal charges will not be filed against a former California Highway Patrol officer who was caught on video allegedly assaulting a mentally ill homeless woman on the side of a freeway, the Los Angeles County District Attorney’s Office announced Thursday.

“Based upon the facts presented, there was a lawful necessity for (Officer Daniel) Andrew to use force to prevent (Marlene) Pinnock from entering the lanes of traffic and there is insufficient evidence to prove beyond a reasonable doubt that the force he used was unreasonable or excessive,” a Charge Evaluation Worksheet (PDF) from the District Attorney’s Office stated.

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Andrew resigned from the CHP when the agency reached a $1.5 million settlement with Pinnock.

The 42-second video of the incident drew outrage from civil rights activists, community leaders and Pinnock’s family. District Attorney’s officials said that while the video – which was shot by a motorist driving by – may have been “unsettling to watch, the recording does not capture the series of events leading up to Pinnock’s detention.”

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The District Attorney’s office says its determination was made based on medical records, eyewitness accounts, recordings of 911 calls and multiple patrol car dash camera videos of the incident, which began at 7:11 p.m. on July 1, 2014 with a 911 call reporting a pedestrian walking on or adjacent to the 10 Freeway and ended with Pinnock’s admission to Los Angeles County Medical Center at about 9:30 p.m. that night.

“When looking at all of the evidence, and especially the medical reports and eyewitness accounts, it becomes exceedingly clear that the officer, who was alone and struggling with Ms. Pinnock precariously close to evening freeway traffic, acted within the law,” District Attorney Jackie Lacey said in a statement. “In our analysis, his use of force was legal and necessary to protect not only his own life but also that of Ms. Pinnock.”

At least four civilian eyewitness contacted authorities on their own after the video was publicized in defense of Andrew, according to the District Attorney’s office.

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Three eyewitnesses told investigators they saw Pinnock strike Andrew, while four of them said they thought he was trying to save her from wandering into traffic and being killed or injured.