Psychopathic killer stalks Glasgow--in a downbeat police procedural that mixes documentary-like chunks of routine with glimpses (fairly pallid or clichÃ‰d) of policemen's home lives. The victims seem to have no connection with each other--they're men, women, young, old--but all are stabbed and all are marked with the message ""This is for Lissu."" The only other clue: a vague description. . . until the police receive a tape-recorded, partly guitar-and-vocal message from the apparent culprit. Much legwork goes into analyzing this missive, of course: voice experts, an undercover search for guitar-players, etc. But the whole thing eventually turns out to be a hoax, while other hunches prove equally off-base. And it's only when the psycho kills his own social worker that the cops can finger him--after which they bait a trap for him, using policewoman Elka Willems (who, in the primary homeplot, has been having a tender affair with unhappily married Detective-Sgt. Sussock). With no real explanation of the vendetta, this is somewhat disappointing in plot--especially since, though perhaps authentic, the fact that all the sleuthing leads nowhere is unsatisfying. And most of the personal cop-vignettes are drab. But the gritty detection and Glasgow drear are moderately effective, even if never in a class with William Mcllvanney's Glasgow classic, Laidlaw (1977).