Washington (AFP) – The parents of a teenager who shot dead four people at a high school in Michigan had ignored the boy’s psychiatric problems and his calls for help, witnesses told a US court Tuesday. Ethan Crumbley, 15, killed four people and injured six more at his school in Oxford, north of Detroit, on November 30, using a gun his parents had bought him days earlier. After trying to flee, parents James and Jennifer Crumbley, aged 45 and 43, were charged with manslaughter, a charge very rarely used in such cases. On Tuesday, they appeared handcuffed and with their legs shackled, before a…