SAVANNAH, Ga.—Ahmaud Arbery’s mental health records can’t be used as trial evidence by the three men who chased and killed the 25-year-old man as he was running in their neighborhood, a Georgia judge ruled Friday. The decision by Superior Court Judge Timothy Walmsley further limits defense attorneys’ efforts to portray Arbery as an aggressive young man with a troubled past when the case goes to trial soon, with jury selection scheduled to start Oct. 18. The judge ruled that Arbery’s medical privacy, even in death, trumped the rights of the men standing trial to a robust defense. And he concluded that a registered nurse’s “highly questionable diagnosis” that Arbery suffered from mental illness during his first and only visit to a mental health services provider in 2018 could unfairly prejudice a trial jury. “There is no evidence that the victim was suffering from any mental health issue, or had otherwise …