I can guarantee you this happened as I was in the car. 37 in a 35 (school zone). We couldn't believe it and the cop proceeded to chew his ass telling him how he was endangering the lives of kids and how he was lucky that he didn't write him a ticket and that 35 meant 35. He is no longer employed with Rogersville along with several others. My wife (girlfriend at the time) got one for doing 61 in a 55. Her uncle was the mayor and had it fixed. He fired a couple of them and hired some new folks not long after he was elected. They were truly dicks and I tend to not say that about law enforcement as I have several friends in that line of work and they are all good people just doing their job.
Where I worked, the majority of the tickets were written in a 40 mph zone, and we were supposedly known for writing lots of tickets. When I was being trained, I wrote a guy (the first ticket I ever wrote) for going 55 in a 40. Afterwards, my training officer said "I'm not telling you you can't write them for that, but "our speed limit" through here is generally 60 before you get a ticket." After that, that was my "limit". 60 in a 40, 45 in a 30...basically 50% over the posted speed limit. In the neighborhoods, where it was 25, maybe the limit was 35, but I don't recall writing too many in the neighborhoods...we're weren't supposed to harass the locals. Although it was fun to get complaints from the locals about speeding, and them want "extra patrol". I can't tell you how many times I caught the complaining party speeding. Or, they'd invite you to sit in their driveway, and they point out cars coming that they'd say "they're flying!" only to be right at the speed limit when I showed them the radar.
Just had traffic court this morning. Didn't see a single ticket for anything less than 12 over. That's troopers and county deputies.
Maybe it's just the areas I've worked, but generally speaking, every cop I've ever known, or worked with would give you AT LEAST 10mph over.
JME, YMMV. I've written, defended, or prosecuted literally thousands of tickets in jurisdictions all over central AL, and have NEVER seen what you speak of. I'm not saying it doesn't happen, just that I've not seen it, ever. Not in Jefferson (including every municipality there), Shelby (including every municipality there), Cullman, Walker (and some municipalities) St. Clair, Blount, Autauga, Chilton, Bibb (and it's municipalities), Dallas, Perry, Tuscaloosa (County and City) Wilcox, or Hale counties, where I've either policed, defended, or prosecuted.