PONTIAC, Mich.—A 15-year-old boy accused of killing four students at a Michigan high school will remain in adult jail while awaiting trial, a judge said Tuesday, rejecting a request for his transfer to a facility for teens. A transfer would be a burden for the understaffed Children’s Village and too risky for others there, Oakland County Judge Kwame Rowe said. Ethan Crumbley’s “basic needs are being met at the jail,” Rowe said. “He has food, water, television, books, showers, and communicates with the public and family members through electronic communication.” The judge noted that Crumbley stays at a clinic inside the county jail and is kept away from adult inmates. Rowe said the teen’s emails are generally positive. Crumbley is charged with murder and other crimes in a mass shooting at Oxford High School on Nov. 30. His lawyers said they will pursue an insanity defense. Separately, James and Jennifer …