Woman guilty in pair of stabbings, one fatal

A homeless woman accused of stabbing two people in San Francisco in disputes over portable toilets was found guilty Wednesday of second-degree murder, assault with a deadly weapon and other charges.

Lizette Cauich, a 25-year-old Los Angeles native, wiped away tears as the verdict was read in the unusual case in which she admitted to killing 58-year-old Mitzi Campbell in June 2016 in a crime captured on video.

Cauich took the witness stand in Superior Court in her own defense, saying she stabbed the flagger at a South of Market construction site in self-defense after Campbell pulled her hair — an assertion disputed by prosecutors.

Cauich’s boyfriend, 44-yearold Oscar Mendez, was found guilty of accessory after the fact in Campbell’s killing and assault with a deadly weapon in another daylight stabbing that he and Cauich committed 12 days earlier in the Tenderloin.

The Los Angeles couple with a tumultuous past had agreed to meet in San Francisco in May 2016 to reconcile. Jobless and homeless, they drank 40-ounce beers and used methamphetamine during the day while staying in shelters at night.

Their bout of violence started May 29, when Cauich approached a parking lot at Eddy and Taylor streets to use the portable toilet. When worker Amar Dahmi refused her, she whipped out two knives and attacked, prosecutors said.

The worker fended her off with a trash can, but she returned with Mendez and another man. They stabbed Dahmi several times before he stumbled away toward the Tenderloin police station. Dahmi survived and testified in the case.

The attackers weren’t caught by June 10, when Cauich approached a construction site on Shipley Street near a Shell station. The workers sent her away, and in security video from a nearby store, Cauich is seen repeatedly stabbing Campbell.

Campbell, a grandmother whose family members held vigil in the gallery every day of the trial, fell dead at the scene.

Defense attorneys argued that Campbell’s pulling of Cauich’s hair triggered the defendant’s post-traumatic stress disorder. Cauich was said to have suffered years of sexual and physical abuse, causing her to quickly turn to violence to protect herself.

The defense, though, presented no video or eyewitness evidence that Campbell had assaulted Cauich.

Mendez arrived at the scene and attempted to escort Cauich away. He was found guilty of accessory as well as possession of a dirk or dagger.

Cauich was found guilty of assault with a deadly weapon in the attack on Dahmi. The jury could not reach a unanimous verdict on whether the couple committed attempted murder in that incident. The San Francisco district attorney’s office must decide whether to retry the couple on the charge.

A sentencing date has not been set. Evan Sernoffsky is a San Francisco Chronicle staff writer. Email: esernoffsky@sfchronicle.com Twitter: @EvanSernoffsky