Hornet's Nest by Patricia Cornwell

Deputy Chief Virginia West likes and respects her boss, Hammer, but with an increasing number of visiting businessmen being murdered in her city by a maniac with a penchant for painting his victims bright orange, she finds it hard to accept Hammer's edict that a rookie reporter should ride on patrol with her to better relations with their citizens. Her worst fears are confirmed when the reporter, Brazil, presses the button to activate the boot-release rather than the siren on their first outing. He's not the only blight on her life right now: her cat's angsty, her hormones are misbehaving, her opposite number in the uniformed division is behaving like a jackass, the radio despatcher is determined to trip her up, the D.A. is in the middle of a hot battle with the trial schedule. And orange coloured corpses keep turning up on her patch.