How was b. t. k. caught?
DNA tests showed a "familial match" between the pap smear and the sample from Wegerle's fingernails; this indicated that the killer was closely related to Rader's daughter, and combined with the other evidence was enough for police to arrest Rader.
Dennis R Rader, B.T.K, was arrested on February 25, 2005 after he sent a floppy disk to police that could be traced back to the church where he had computer access. Based on that, police obtained DNA from a Pap smear from Rader’s daughter which provided a familial match and lead to his arrest.