Crimson Joy — Robert B. Parker

Spenser is back on his home turf: a Boston of sleaze and surprises, dangerous days and deadly nights. A serial killer is on the loose in Beantown and the cops can't catch him. Called the "Red Rose Killer" because he leaves a long-stemmed red rose on each woman he slays, he's terrifying every female who has to go out after dark. But once Spenser joins the chase, the murderer's trail turns toward home when a rose is left for Spenser's own Susan Silverman.