Freaky Deaky by Elmore Leonard (1988) Arbor House

An officer in Detroit, assigned to the bomb squad, asks for a transfer to satisfy his girlfriend.  He ends-up in sex crimes, she kicks him out, which gets him suspended since he doesn't have an address in Detroit.  In the meantime, a man and a woman who used to know each other in the old, protest movement days, conspire to con someone they knew who in inherited millions by scaring him with bombs.  Bombs kill people and our ex-cop hopes to catch the killers and get his job back.