ROCHESTER HILLS, Mich.—The parents of a Michigan teen charged with killing four students at Oxford High School were scheduled to return to court Tuesday on charges of involuntary manslaughter. A probable cause conference was scheduled in Rochester Hills District Court for James and Jennifer Crumbley. Police said the Oxford, Michigan, couple was found Dec. 4 hiding in a commercial building in Detroit after warrants were issued for their arrests. They’re jailed on bond of $500,000 apiece. Probable cause conferences typically are procedural and involve discussions between defense attorneys, prosecutors, and a judge on bond and other matters. Their son, Ethan Crumbley, is charged as an adult with murder, terrorism, and other crimes. His probable cause conference was adjourned from Monday to Jan. 7 to allow his court-appointed lawyer to review evidence including witness statements from the Nov. 30 shooting that also left six other students and a teacher wounded. James …