The judge in the Yosemite homicides trial in San Jose says testimony could end next week. Yesterday marked the end of the fourth week of trial for confessed killer Cary Stayner, who’s accused of killing Carole Sund, her daughter, Juli, and Argentine friend, Silvina Pelosso. Stayner has pleaded innocent by reason of insanity. Several doctors have testified for the defense this week that Stayner has abnormalities in his brain. Doctor Monte Buchsbaum of the Mount Sinai School of Medicine in New York testified yesterday that he agreed with another doctor’s findings that Stayner had diminished brain activity in the region that controls impulses and plans actions. But on cross-examination, Buchsbaum said he had no idea how Stayner behaved around the time of the killings.