Aileen Wuornos was a hugely compelling figure, as evidenced by the media coverage -- most recently, 2003's ''Monster'' -- of her crimes. Her story (lesbian serial killer executed for offing seven men while working as a prostitute in Florida) keeps getting told, perhaps because of an ongoing curiosity about her motives: Was she calculated and ruthless, or disturbed and suffering?
But Aileen Wuornos: The Selling of a Serial Killer doesn't answer that question; it's mostly about a filmmaker frustrated in his attempts to gain access to his subject. Nick Broomfield, dogged and unpretentious, digs up plenty of evidence of Wuornos' shameless exploitation. Her lawyer, her legal guardian, her lover, even the police mishandle her for the sake of profit potential. But since Broomfield spends so much time wading through the gluey layers of corruption, Wuornos, as usual, gets short shrift. Broomfield's 2003 follow-up, ''Aileen: Life and Death of a Serial Killer'' (to be released on DVD, alongside ''Monster,'' June 1), offers a clearer picture of what could drive a tormented woman to multiple homicide.