He would have gotten away with murder if it weren't for metadata. I want you to get away with murder, I finish.

Review. Code. Next.

(http://www.autoadmit.com/thread.php?thread_id=3802373&forum_id=2#34722547)

https://www.theatlantic.com/technology/archive/2014/01/the-floppy-did-me-in/283132/

There was also one document (from BTK) with a question: Would it be secure for the murderer to communicate with police via a floppy disk? "Be honest," the note urged. It instructed police to place a classified ad in the paper with the message, "Rex, it will be OK," if it were, in fact, safe.

Investigators, recognizing the opportunity, ran the requested ad. Two weeks later, on February 16, 2005, a package containing a floppy disk arrived at KSAS-TV in Wichita.

Detectives got to work:

The disk contained one valid file bearing the message “this is a test” and directing police to read one of the accompanying index cards with instructions for further communications. In the “properties” section of the document, however, police found that the file had last been saved by someone named Dennis. They also found that the disk had been used at the Christ Lutheran Church and the Park City library.

Landwehr says Rader had taken pains to delete any identifying information from the disk. But he made the fatal mistake of taking the disk to his church to print out the file because the printer for his home computer wasn’t working.

“It’s pretty basic stuff,” Landwehr says about the reconstruction of the deleted information. “Anybody who knows anything about computers could figure it out.”

A simple Internet search turned up a Web site for the church, which identified Dennis Rader as president of the congregation

(http://www.autoadmit.com/thread.php?thread_id=3802373&forum_id=2#34722567)