EORENSICS CASEFILE: CATCHING THE BTK STRANGLER Dennis Rader was an Air Force veteran, church council president. and Cub Scout leader. But most people now know him by the name BTK, which stands for the method he used to systematically murderten people between 1974 and 1991: Bind, Torture, Kill. Over those 17 years, BTK terrorized the public by sending taunting letters to local media outlets and claiming to be driven by the same dark energy that guided Jack the Ripper, the Son of Sam, and the Hillside Strangler. After 1991. however. BTK went silent, and the case went cold. No fingerprints. No eyewitnesses. No leads. Just a jagged rip of loss and fear through the metropolitan area around Wichita. Kansas. where BTK had committed his murders. when BTK resumed his communication with the media in 2004, he overlooked a critical fact: this was now the 21 st century. and law enforcement officers were becoming increasingly adept at forensic science. Over the course of 11 letters and packages sent by BTK during 2004 and 2005. law enforcement officials slowly began filling in the blanks. BRINGING BTK TO JUSTICE WITH FORENSICS ETK's first 2151 centum communique was a letter sent E Wichita Eagle that included crime scene photos and a driver's license belonging to a victim from 1986. This victim had not been definitively linked to BTK until then. Armed with the new connection to the BTK case. police collected DNA from under the victim's fingernails, and launched a campaign that tested hundreds of local men for a possible match. In another package intended for law enforcement, BTK used a dropeoff point that was within view of a nearby store's surveillance camera. Grainy footage showed a blurry figure dropping off the package and leaving in a black Jeep Wfinal piece of the puzzle came in the form of a purple WHOM! disk that BTK sent to a local Fox TV affiliate. He didn't believe that the information he included could be traced. But it was the information he'd deleted that interested forensic investigators: metadata embedded in a deleted document contained the words Christ Lutheran Church, and attributed the last edits made to someone named Dennis. From the time investigators received the floppy disk, it tookjust nine days to put the case together. They learned that Christ Lutheran Church had a council president named Dennis Rader. Further reconnaissance found a black Jeep Cherokee outside of Rader's home, matching the one caught on surveillance from an earlier package's drop Wcircumstantial evidence wasn't enough, so investigators obtained a warrant to test the DNA of a close relative: Rader's daughter. who'd had a pap smear done at Kansas State University's medical clinic. DNA tests done at a lab in Topeka revealed a familial match to the DNA under one of BTK's victim's fingernails (the victim who had not been previously linked to BTK until his letter to The Wichita Eagle). The chain of evidence was clear: Dennis Rader was BTK. Dennis Rader was arrested on February 25, zoosiover 30 years after the investigation had begun. In his interrogation, Rader said, while confessing to all ten murders he'd committed, "The floppy did me in.\