Just a random guess, but they may have been hunting for a self-incriminating admission of drunk driving. I got pulled over for speeding once, and the first thing the cop asked was "Why do you think I pulled you over?". I shrugged, and said I had no idea. He claimed I was speeding, but let me off with a warning. In another instance where I got pulled over for speeding[1], the cop told me as much, but then asked how fast I thought I was going. I told him 65 (which was 10 over the limit of 55). He claimed that I was going 70 (15 over 55), but wrote me a ticket for 65 in a 60 zone (5 over, notice that he went with the speed that I claimed, but changed the speed limit in my favor). Apparently the fine varies based on the amount over the speed limit, so he basically gave me a lower fine. My hunch, is in both cases, they were just looking for admission of guilt.

[1] Just so people don't get the wrong idea, I am generally a very cautious driver, there were the only two speeding related encounters in 15+ years.

Never say a number. If you want to give the option to the cop to give you a ticket with a lower fine attached, just say "my speedometer said I was okay." And that will probably result in a citation for an equipment violation instead of for speeding.

You can't say "I don't know," either, because that sets you up for some variation on negligent driving.

The safest response for the court record is "I don't answer questions without legal counsel present," but that is likely to provoke the cop into ensuring that there will be a court record.

> "Why do you think I pulled you over?"

That's pretty standard; nearly every traffic stop I've witnessed or heard about contains that line.

I believe they do it because -- assuming you give a truthful/correct answer -- it makes it less likely you'll contest the ticket, and if you do, they can tell the judge, "when I asked why they thought I'd pulled them over, they told me it was because they were speeding". If you admit to the infraction, you don't really have much of a leg to stand on in court.

And the de jure standard answer is "because you had a reasonable suspicion I was committing a crime," or "I don't answer questions without legal counsel present."

Of course, since many cops will retaliate against smartasses, the de facto standard answer is "I don't know. Why did you pull me over?" This is always truthful, correct, and non-incriminating, because you can't be expected to read the cop's mind.

Yep, totally. I usually use the wording "I'm not sure", or, better, "I can't be sure", since "I don't know" is often not entirely truthful.

If I had to guess, driving slow. Her pulling over instead of speeding up was smart, but mildly suspicious to a cop without an active call.