Police in game already have a ton of paperwork. The other night after I was done playing I did 90 minutes of paperwork outside of the game. Between writing a duty report, ADAM report, arrest reports and impound reports to release people's vehicles, plus an email to the cadet I had with me, and a copy to the commanding officer for his records. That doesn't even account for the SWAT officers, helicopter operators, high speed or heavy pursuit vehicles, traffic enforcement, investigators and Detective paperwork.
I do not arrest people based off of a civilian's report alone. If he comes to me and says "that guy just robbed me for $8,864 and my heavy pistol" then I search the guy and find exactly that... Do I arrest him or let him go? Detain him and search him while I investigate? If the victim then says they have a video, great! I'll detain the suspect, review the evidence and make the arrest.
If another cop says to me "that guy has an illegal gun" then I'm going to arrest that guy. A cop's word is higher value to me than a civilian's.
The other day an RP situation happened where one person claimed that another hit their car intentionally and wouldn't take care of the damages. The "suspect" denied it so I RP'd looking for accident damage which he played out with me, luckily.
At the end of the day if you're going to commit crimes and get caught, I don't think you should get to whine about if there is "evidence" or not. If you flee the drug lab and have a bunch of LSD on you when you're caught, you're getting a charge for manufacturing if you were seen actually manufacturing or not!