How many days a week does a criminal investigator work?

It depends on for whom the criminal investigator works. Federal law enforcement criminal investigators, such as agents of the F.B.I, A.T.F. and I.R.S., work a mandatory minimum 50 hours per week. State and local governments have different work schedules, but most work a 40-hour week and, when necessary and authorized, work overtime hours. Generally, most criminal investigators are on-call on a 24/7 basis. They do get paid for overtime hours worked.