SAVANNAH, Ga.—Defense attorneys for the men charged with killing Ahmaud Arbery won’t be allowed to present evidence of the slain black man’s past legal problems when their clients stand trial for murder, a Georgia judge ruled. Gregory and Travis McMichael, a father and son, and their neighbor William “Roddie” Bryan Jr. are awaiting trial this fall for chasing and killing 25-year-old Arbery last year as he ran in their neighborhood outside coastal Brunswick. Jury selection is scheduled to start on Oct. 18. Attorneys for the McMichaels wanted the jury to hear about Arbery’s past run-ins with law enforcement, including two arrests. They hoped it would bolster their case that the white men reasonably suspected Arbery had committed a crime when they began the pursuit that ended in his death. Prosecutors argued that Arbery’s criminal record and other prior problems should be kept out of the trial, saying they are irrelevant …