I was an officer for 25 years. I filled in as a shift supervisor as needed, including my longest stint of 6 months. Here are some of the things I saw from my perspective:
- always backs his/her officers. Is an ADVOCATE for the officers when dealing with management.
- Looks out for the safety and well-being of the troops, and their professional development (continuing training)
- gets to know their officers.
- stays current on laws and regulations
- is fair and impartial. no playing favorites when granting leave time or making assignments, although assignments need not be "Equal." For example, an officer who is weak on making traffic stops may be given extra assignments doing traffic.
- does NOT micro-manage - lets the officers do their jobs, makes "suggestions" as needed, rather than telling them what to do. Better yet, helps the officer to walk through the thought process involved and arrive at the correct course of action on his/her own
- Makes sure that there is probable cause and the elements of the offense are articulated when approving officers' reports
- keeps management/gov't authority (city manager, etc), apprised on an as-needed basis, of high-profile cases (Doesn't let the chain-of-command get blind-sided)
- Does his/her best to make sure the officers don't leave themselves open to liability, and that the department/gov't entity (city, etc) are not exposed to liability
- Has self-confidence, but not arrogant.
- Has an appropriate sense of humor.
- Uses disciplinary measures sparingly, and uniformly
- Is not afraid to pitch in and be a working officer when the agency is short-staffed, taking some of the load off the officers.
I'm sure there's more, but that's a start! Hope that helps! Basically, a first line supervisor is caught in the middle between management and patrol. He has to please them both.