Several years ago I took a job working for a large telecommunications firm as the desktop support manager, and somehow I got assigned to the most loathsome of all duties in our shop: hardware inventory clerk. I was elected in true democratic fashion, being nominated and appointed while on vacation.
On her way out the door, the outgoing clerk told me that something strange was going on: In spite of her best efforts, inventory "irregularities" kept occurring. My boss, the IT manager, told me that the outgoing clerk's poor clerical skills were responsible. I was determined to do better, so I shifted from her weekly inventory to a daily one.
Sure enough, my inventories kept coming up short. One afternoon, right after a couple of new laptops had been delivered, I ran my inventory. The next morning I did another one, and discovered that I was two laptops shy; no machine deployments had taken place in between.
Only two people had swipe-card access to the hardware room: me and my boss. There was also a key in my desk drawer that opened the door, but using it set off an alarm at the security desk. I checked the automated access log, and sure enough, that key had been used at approximately 3 o'clock that morning. Apparently the alarm had sounded, but there was no entry written in the security log. Archived records showed similar occurrences during the past year and a half. I cross-checked the data and found a correlation between "incidents" and two of our guards -- who obviously didn't know about the automated access log.
Convinced that I had solved the case, I scheduled a meeting with the director of security. I presented my findings piece by piece, built my case slowly, and concluded with my theory that the two guards were thieves. I turned expectantly toward the security director ... and noticed a strange frown on his face. He declared that the evidence was circumstantial, gave me a hard look, and demanded to know how he could be sure I wasn't committing the crime myself!
This wasn't going the way I expected -- although I guess one of the standard detective plots involves the PI suddenly finding himself cast as the prime suspect.
I pointed out that equipment had been disappearing for months before I came on board, reminded him that his security detail was experiencing multiple alarms on a secure door without reporting it, and looked over at my boss for some support. The best I got was a meek assertion that he didn't believe I was a crook, but he didn't want me accusing other people without evidence. Finally, they asked me to the leave the room so they could "discuss options."
My boss never mentioned the subject to me again, even when I submitted a backdated spreadsheet of shortfall items averaging about US$3,000 a month. The thefts slowed during the next few weeks, but they never stopped. Then I was reassigned; the position of inventory clerk passed to a co-worker. I showed him my shortfall spreadsheet, as well as all the data I'd collected, and suggested he keep them updated.
I also passed along a proverb that would make a good title for a detective story, in which the hard-boiled investigator discovers a pattern of corruption starting right at the top: A fish rots from the head.