The Plymouth County Attorney is increasing the charges against a Le Mars man who allegedly killed his baby son. 21-year-old James Boldra was originally charged with child endangerment in the death of Trevor Boldra on February 13th. Trevor Boldra was the first baby born in the new millennium in the county. Plymouth County Attorney Darrin Raymond says the charge has been upgraded to first degree murder. After six weeks of investigation, officials believe the death of Trevor was caused by “shaken baby syndrome.” Raymond would not elaborate on what evidence leads them to believe James Boldra killed his son.Raymond says at this time, Boldra is the only suspect in the child’s death.Boldra will be arraigned on the charges on Monday.