A man who gunned down his mother with a 12-gauge shotgun as a crowd of people gathered on the street outside his San Luis Obispo apartment is guilty of second-degree murder, a jury decided Tuesday.

The jury found Christopher Shumey not guilty of the weightier first-degree murder charge.

Now, in a second phase of Shumey’s trial, the jury will have to decide whether he was sane at the time of the murder.

Shumey, 36, was also convicted of assault with a deadly weapon on a peace officer, the result of firing his gun toward a San Luis Obispo police officer who responded to the original shooting.

Shumey has a history of mental illness dating to 1999, according to court testimony. His mother, Karen Shumey, went to his apartment on Sept. 17, 2011. After the two quarreled, Karen Shumey left the apartment for 20 minutes so her son could cool off. When she returned, he shot her twice as she stood on his balcony.

The last local defendant charged with murder to pursue an insanity defense was John Woody, charged with stabbing a man to death at a Paso Robles Laundromat. While Woody had a long history of mental illness, last November, a judge ruled that Woody was legally sane at the time of the stabbing. The previous February, another judged ruled that Kenneth Cockrell was sane when he bludgeoned his 66-year-old wife to death in Atascadero.

Both defendants received life prison terms.

On the same day that Cockrell was found legally sane, Andrew Downs was sent to Atascadero State Hospital, just days after he was declared not guilty by reason of insanity for murdering two sisters on Christmas Day 2010 at the Santa Margarita Ranch.

Downs, the last local murder defendant to successfully pursue a not guilty by reason of insanity plea, believed that a government takeover was in progress and suspected that the police, the military and aliens were involved, doctors testified during the trial.

Many of the same psychiatric witnesses to testify at those trials are expected to testify in the Shumey trial as well.