Possible Clues:

• Encourage Robert to be a murderer, by the sound of it, and he'll go rapidly downhill
• Just a bit of business for the expert
• Completely skilled
• Bit of business that's not for the novice
• One very skilled at work
• Such a bit of business is not for the uninitiated
• Expert from a small admin. branch
• Appropriate holding of French expert
• Particularly skillful
• A sector of government that's proficient