A Marathon County judge has held a Marshfield woman over for trial on a first-degree reckless homicide charge.  Twenty-seven-year-old Cassandra Staab is suspected of supplying the fentanyl-laced heroin which killed a Spencer man last year.  The judge ruled Monday prosecutors had presented enough evidence for him to order the trial.  Twenty-two-year-old Thomas Bychinski died January 31st, 2017.  Witnesses told investigators Staab was their dealer when they bought heroin.