Normal people don't speak hex. User number A00 would be too confusing in most cases.
Remember stuff like this needs to be cop-proof. I used to design software for their dispatchers to use, and they aren't super intuitive with computers for the most part, like most of the other cops unless it's specifically part of their job. A lot of things had to be dumbed down so they could use and understand it easily.
No insult is meant here, it's just they are very busy with their jobs and having to be familiar with many different tools and systems; radio, weapon(s), forensic stuff, etc. so the amount of time they have to invest in training and learning about new tools has to be balanced among many competitive things they need to be current on. Plus, in an emergency situation, they want tools they don't have to expend a lot of extra thought on how to use.
Hence, anything designed for them to use has to be reasonably fail-safe, intuitive to use, bulletproof and easy to understand to be successful. My software was used for over 10 years by several local departments, so I'd consider that a success.