HALF MOON BAY (KCBS)— The family of an 18-year-old woman, shot and killed by a San Mateo County Sheriff’s Deputy in June, filed a federal lawsuit against the department on Tuesday.

The Mother, father, brother and dozens of other family, friends and supporters of the victim appeared at a news conference held at Maidenhair Walk in Half Moon Bay, the site of where Yanira Serrano died.

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Some held signs that read, “Stop police brutality” and “Justice for Yanira”.

The family’s attorney Arnoldo Casillas said Serrano, who suffered schizophrenia, posed no threat to Menh Trieu, the deputy who shot her on June 3rd.

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Last month the San Mateo County District Attorney decided not to pursue charges against Trieu. Casillas said a civil case is the family’s only remedy.

“There was no reasonable basis to shoot her. Yanira Serrano was five-feet tall. She weighed 200 pounds. She had a congenital birth defect; essentially a clubbed foot. She couldn’t run,” said Casillas.

It was Serrano’s brother who called 911 that night to report that she hadn’t taken her medication that night and was acting out and yelling. When the deputy arrived, she reportedly ran outside toward him with a kitchen knife. That’s when she was shot.

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The District Attorney determined the killing to be legally justifiable. This suit, filed in San Francisco claims the shooting was unconstitutional. The suit calls for better training of officers when dealing with the mentally ill.