The name on the floppy disk

Step by step

1. 01

   A reliable sourceOpen source

   The ABA Journal's 2006 article tells the case from the start. Before his arrest BTK asked police whether a floppy disk could be traced; as he asked, police placed the ad “Rex, it will be OK”.

2. 02

   The vehicle on the security tapeOpen source

   The box BTK left at a Home Depot turned up in an employee's pickup truck. The store camera shows a black Jeep Grand Cherokee pulling up beside the truck. It gives no name on its own, but it is worth keeping.

3. 03

   The disk arrivesInvestigation

   The disk that reached a TV station on 16 February 2005 held one valid file. Police checked the document's “Properties”, its metadata: the person who last saved it was named Dennis. The disk had been used at Christ Lutheran Church and the Park City library.

4. 04

   Two leads, one searchOpen source

   A name (Dennis) and a place (Christ Lutheran Church). A simple internet search found the church's website; the president of its congregation council was Dennis Rader.

5. 05

   A second sourceOpen source

   An AP story from 4 March 2005 describes the same chain: in January Rader brought the disk to his pastor to print a church council agenda. It calls him “the 59-year-old church council president”.

6. 06

   Address and vehicleInvestigation

   Rader was a code compliance officer in Park City. Driving past his house, police saw a black Jeep Grand Cherokee, the same type as on the Home Depot tape. I blacked out the name of the family member it was registered to.

7. 07

   DNA confirmationLab

   A name and a vehicle do not prove identity. Before the arrest, prosecutors subpoenaed a tissue sample from his daughter's medical records; the result showed it came from BTK's daughter.

8. 08

   Nine daysInvestigation

   The disk arrived on 16 February; the arrest came on 25 February 2005. In June 2005 Rader pleaded guilty to 10 murders and received 10 consecutive life sentences.

Calculations

• Disk to arrest: date(2005, 2, 25) − date(2005, 2, 16) = 9 days.

Limits

• Sources differ on which file carried “Dennis”: the active file or a deleted agenda file.
• The map shows the area, not the house; the name of the family member the vehicle was registered to is blacked out.

Sources

• ABA Journal · How the Cops Caught BTKMark Hansen, 1 May 2006
• Lawrence Journal-World / APSharon Cohen, 4 March 2005
• Legaltech News · David Kalat7 October 2019; the date the disk arrived
• Esri World ImagerySatellite imagery: Esri, Vantor, Earthstar Geographics, GIS User Community. Acquisition date not verified.