The "demon barber of Fleet Street" has wielded his fatal razor on stage, screen, in song and in print since the 14th century, and now, on television, "Sweeney Todd" is this week's "Mystery!" offering (tonight at 9 on PBS). This version, produced by Thames Television, is heavier on psychology than blood, presenting a madman rather than a ghoulish killer.

Indeed, the screenplay by Vincent Tilsley, an adaptation of the Victorian version by George Dibdin Pitt, leaves open the question of whether Sweeney Todd murdered anyone at all. The legend, of course, is about a barber who calmly sliced the throats of unfortunate customers, usually members of the upper class, dispatched them to his cellar by means of a cleverly designed trap door under the barber chair, and then sold the ground-up remains to a neighbor famous for her delicious meat pies. As host Vincent Price tells us, there are many incarnations of the story, including a real case in France around 1800, and a 16th-century Scottish family found to have robbed, murdered and eaten more than 1,000 people.

The story is so gruesome it really defies interpretation, and perhaps serves better as a scary tale than an illustration of how young minds can be warped if sent to a Victorian workhouse, as this version would have it. Through flashbacks we see a young Todd imprisoned by a sadistic workhouse master, and this traumatic episode apparently prompted him in later life to murder rather than be called a thief.

It is almost too apparent from the outset, when Todd tells a prospective customer that the white stripes on the barber pole represent bandages and the red stripes blood, that he is insane. British actor Freddie Jones plays him as a somewhat pathetic madman--never pathetic enough to deserve our complete sympathy, but a man possessed by the demons of his unfortunate childhood.

The ambiguity, created with scenes that seem to reveal contradictory versions of the truth, is confusing rather than intriguing. The producers would have done better to forgo analysis and concentrate on the pure horror of the case and the stench of rotting flesh, which leads ultimately to Todd's unmasking.