In most cases I completely agree. At least you know what to expect, if you have a past drug conviction and get pulled over, expect to be searched.
I can see this being the case if the officer knew that the person they were pulling over actually had a past conviction, either based on records he was able to search, or even personal experience with the individual. But I'm curious about whether or not the individual has a responsibility to disclose that information to the officer upon being asked about things in his/her past.
Will the officer actually say or write in a report the search was conducted "because of a past conviction"? Absolutely not. There will of course be slurred speech, bloodshot eyes, smell of marijuana or any number of reasons.
Yes, this is to be expected if the individual was actually caught in the act of using, or being under the influence of drugs or alcohol. It would be evidence of a current wrongdoing, and something the officer can see for himself right then and there.
You only have the rights you can afford to defend.
And whatever a judge agrees with. But that's getting down to what I'm asking about. If a person is stopped by police and is asked whether they've been arrested in the past, do they have to divulge that information, and can it be used against them in some way that a judge would agree with?