Between 1974 and 1991, the BTK killer taunted police with letters boasting of his atrocities but yielding few clues to his identity. The serial killer resurfaced in 2004 and police corresponded with him in an effort to gain his confidence. In one of these communications, BTK sent detectives a purple floppy disk containing an ominous warning.
The BTK task force enlisted the expertise of Det. Randy Stone in the Wichita (Kansas) Police Department's Computer Crimes Unit, who checked disk properties and learned the previous user's name was Dennis. Further examination revealed the disk was last used at Wichita's Christ Lutheran Church. After a quick search of the church's Web site, Stone learned there was one Dennis among the church officers - Dennis Rader.
The knowledge tipped the investigation in law enforcement's favor, where DNA evidence linked Rader to 10 murders. In August 2005, the courts sentenced him to 10 consecutive life sentences. Stone's digital detective work had cracked the decades-old case in a 15-minute forensic examination.
Stone rates his computer forensics work in this case as a three on a scale of one to 10, and stated in a 2007 "Popular Mechanics" article that, "As simple as that was, the sad thing is 95 percent of law enforcement in the U.S. could not have done something like that."
Though digital evidence has lead many cases to similar resolutions, Stone says the state of affairs he described two years ago remains largely true today. "A lot of agencies recognize the need for computer forensics capabilities but often cannot afford to add them," he says. "There are many departments where the forensics guy wears multiple hats. He is the D.A.R.E. officer, the third-shift patrol officer, the forensics guy, the cell phone guy, and works for the volunteer fire department too."
While regional task forces help local agencies deal with the proliferation of digital evidence, it is not enough, says Rich Harris Jr., director of High-Tech Crime Training Services at SEARCH, an organization focused on identifying and solving information management challenges facing public safety agencies.
"The feedback we are getting from across the country is the model of having regional task forces is good but most of them are overwhelmed," he says. "There just isn't enough base knowledge in local departments, so every single device or computer that pops up in every investigation needs to be sent to a task force."
Los Angeles Sheriff's Department Lt. Rocky Costa, who heads the Southern California High-Tech Crimes Task Force, warns while these specialized teams shoulder most of the high-tech investigations load, every law enforcement agency must prepare to handle these cases. He emphasizes technology touches nearly every crime today. Digital media seized in relation to an offense may include everything from computers, flash drives, cell phones, digital cameras and game units, all of which needs forensic examination.
"Criminals don't even think of these things as digital storage devices - it's so much a part of their culture," he says. "That's how much technology touches our lives."
High technology has made the criminal a better criminal, and as Stone points out law enforcement struggles to keep pace. But it's clear the gumshoe of the future will need to be trained to study bytes the way old-school investigators examined fingerprints.
Costa says a task force approach offers a good safety net for agencies lacking high-tech capabilities. "It allows officers to focus on the robberies, the assaults, the murders - the crimes against people," he says. "They can rely on the task force to assist them with technology crimes."