This 26 episode series originally aired July-December, 2002 in Japan, and speculation says that it will probably show up on Adult Swim and definately NOT Toonami. The series does start out slow, but I'm told it picks up after episode 8 (I only have the first DVD). Think of it as The X Files meets Buffy, The Vampire Slayer, only with a serious attitude. You can read the review at Anime On DVD. The description:
Witch Hunter Robin coming to Cartoon Network (2003-11-13 12:14:10)
Following reports on other websites that Witch Hunter Robin will be broadcast on a cable TV channel, ANN has confirmed with 'Johny Walker' that Cartoon Network will be showing WHR later this year or next year.
"In a world where witches abuse their supernatural powers, a special team is tasked with hunting this new threat to society. This organization is known as the STN and comprises of several highly skilled craft users and experts in covert operations. But their most powerful craft user is a young woman named Robin. Her mysterious gift to summon deadly flames will determine the fates of her colleagues and lead her into a dark world of mystique and witchcraft."