1. A journalist conducts an interview.
2. The commissioner investigates/eliminates a suspect.
3. The officer blocks/eliminates a suspect.
4. The serial killer eliminates a suspect.
5. The mafia eliminates a suspect.
6. The doctor arrives and "revives" a player who is technically dead (even if two killers targeted the victim simultaneously).
The presence of an "officer" would somewhat level the playing field between the mafia and the town.