Not really. An old cop told me once that multiple stab wounds are the norm, simply because it takes a few minutes to die of stabbing and people who are trying to kill you by stabbing don't stop until you're dead.
Objection noted, and a reasonable one. Gruesome subject. The assailant intended to murder, as he stabs and stabs until death is obvious.
Still, death by such stabbing still speaks to sexual passion, iirc. Did your friend say what the motives were in those cases of homicide involving many stabbings?