Mollie Tibbetts' accused killer pleads not guilty to murder charges
cristhian rivera was arraigned in poweshiek county district court on murder charges.
the 24-year-old mexican citizen wore headphones and listened to the proceedings with the help of a spanish translator.
last month rivera was charged with tibbetts' murder.
tibbetts vanished in july while out for a run in brooklyn.
her body was later found in a cornfield.
wednesday rivera waived his right to a speedy trial, so a judge set an april 20-19 trial date.
he is in jail on a five-million-dollar cash-only bond.