I started out as a street police officer but ended up doing a job that didn't exist and no one envisioned when I was hired in 1973, a computer forensic examiner. Basically it's a knowledge of data recovery combined with a detailed knowledge of Fourth Amendment search and seizure issues, and rules of evidence and evidence handling as it related to electronic data storage devices.
Many of the legal issues were brand new and there were no precedents for the courts or anyone else to go by. I'm not sure which was the most fascinating, learning all the new-to-me technical issues of data storage or the application of those issues to the criminal justice system. Without boring everyone with a lot of legal mumbo-jumbo, it could get real complicated real fast and caused more than one attorney's eyes to glaze over. We were thrilled when one of the Assistant State's Attorneys went to a computer forensic training class so she'd have at least some idea of what questions to ask.
Edit to add: I didn't vote in the poll, not sure if that answer is "yes", "no" or it should be a "maybe".