By Jorge Casuso

April 2, 2020 -- A state appeals court on Wednesday upheld the conviction of a Santa Monica man for shooting to death a Samohi graduate after a brief run-in near a local liquor store.

In 2018, a jury found Sherwin Mendoza Espinosa, 43, guilty of second degree murder for the killing of 18-year-old Juan Castillo on February 26, 2017 ("Santa Monica Man Found Guilty of Samohi Grad's Murder," August 22, 2018).

But Espinosa was acquitted of the more serious charge of first degree murder ("Man Sentenced in Santa Monica Teen's Murder," October 15, 2018).

Prosecutors said the two men -- who did not appear to know each other -- had a brief argument before Espinosa retrieved a gun from his car.

California's 2nd District Court of Appeal found that "a reasonable jury could have concluded beyond a reasonable doubt that defendant did not actually believe Castillo posed a threat of death or great bodily injury to defendant.

"According to defendant, the shooting was `unintentional' and caused by a `flinch' rather than any overwhelming emotion," the panel wrote in its 22-page ruling.

"And after the shooting, defendant returned to the bar he had previously been at with his friends, and continued drinking and socializing.

"Under these circumstances, the trial court had no duty to give a lesser included offense instruction on heat of passion manslaughter," the panel wrote.

When the chance encounter took place, Castillo -- who had graduated months earlier from Samohi where he played football -- was being driven home from a party, according to his father.

A friend who was in the car panicked when Castillo was shot to death about 12:45 a.m. and drove the victim's body to the second location, where he dropped him off, DA officials said.

His body was found shortly after 5 a.m. in the 1300 block of 16th Street, near the UCLA Santa Monica Medical Center about a mile from the site of the shooting.

The body was spotted by a man walking back to his car who took pictures with his cell phone and called police.

Nearly three months later, detectives arrested Espinosa, who was charged with one count of murder and two counts of being a felon in possession of a loaded firearm.

Investigators tracked the two cars using video taken from surveillance cameras and passing city buses, prosecutors said.

Prosecutors credited Santa Monica police with "really good detective work."

Espinosa is serving a 40 years to life sentence.