I agree with the person who answered above. Make sure your lease/agreement is clearly written. Remember it was his choice to leave.
The general answer to your question is you need to file for custody. This will take some time and there are emergency procedures you can do to try and expedite this process.
I agree with what has been posted. The employer could certainly call law enforcement and let them know about this issue. Additionally, the employer could demand the pay that was given to the employee back and certainly fire the employee for theft.