haunted this community for over 30 years -- >> reporter: the arrest part of a new wave of crimesolving,gynk. to hunt the most violent offenders. 1988, a killer on the loose. taunting police, threatening to strike again. the face of an innocent young girl thrust into the national spotlight, 8-year-old april tinsley, going to play at a friend's house, never making it home. little april kidnapped, raped, and strangled. her body dumped in a ditch. >> i think about april often. i carried her picture in my wallet for a long, long time. >> reporter: the case baffling authorities. the mysterious killer inflicting more fear. leaving rambling, misspelled messages, authorities say, like this carving on a barn door two years after the murder. "i kill 8-year-old april, i will kill again." then in 2004, according to police, more notes left at the homes of other young girls reading, "hi, honey, i've been watching you, you are my next victim." >> how chilling are the details of this case? >> i can assure you that anyone who worked on this case has been haunted by it. >> reporter: investigators say dna from