Years ago, I worked for a security agency running a night patrol service. The patrol car had a scanner installed. As a matter of routine I monitored LPD while working as the company I worked for responded to alarms for an alarm company. Having the scanner going I got a heads up of an alarm and could start heading towards the alarm.
So one night, running a routine patrol and I heard of a break in and an officer down call. Beings that I was a few blocks from the down officer and seeing police car after police go racing past the downed officer, I pulled into the lot and stayed with the officer until his Sgt arrived, then took off to resume my patrol.
A few weeks later I was approached by an LPD Sgt who asked if I had been the security guy that stopped that night. I affirmed that I was and he wanted my name for his report from that night. I gave it to him, thinking nothing of it.
A week or so after that, my boss calls me into his office and hands me a letter from the Chief of Police , recognizing me for stopping and offering protection for the wounded officer. My boss was thrilled because of this letter.
Not long after that, I got stopped by and LPD cop who's first question out of his mouth was "is there a scanner in this car?" I said yes and he started getting all huffy with me, stating that Nebraska law forbid mobile scanners (note: mobile scanners to the best of my knowledge, had never been illegal in Nebraska).
I reached for a copy of the letter that his Chief sent to the office. The very last line inidcated that we had the police deptartments support of using scanners in our cars and that there were no problems with it. I handed that letter to the cop and his face filled with dejection.
The point? Cops are human. They can't and won't know all the laws, though they sure think that they do. What is legal to one cop, another cop may think illegal, as such you are subject to two different interpetations. So, there is no right answer, only wrong answers. It helps to know the law, even if you are aren't doing something illegal with the scanner.
Lately, I haven't even been giving a second look by cops when carrying my scanner. Some of them will ask me what brand it is, and we will get into a little radio talk. Most are pretty cool about it, but I guess there is always one or two who will give a person a hard time for a scanner.