The State Board of Examiners may revoke the surety bond of any public officer or employee:
1. If, after due investigation, notice and hearing, the officer or employee is found to be addicted to gambling, excessive drinking of intoxicants or to the use of narcotics.
2. Upon conviction of the officer or employee of a gross misdemeanor or any more serious crime.
3. When the officer or employee is legally determined to be insane.
4. For any other cause deemed reasonable by the Board.