Some indicators of intent are the juxtaposition of the contraband to other items... for example, Trump had one particularly sensitive document in his desk drawer along with TWO passports (why does he even have two????). WHY was that one document being kept with his passport? what does that say about intent? (it says to me that he intended to flee the Country with something valuable to trade to not get extradited back to the USA)
I seemed to have missed this one.
There are multiple ways to have multiple passports:
1) What you're thinking of--dual citizenship.
2) Diplomatic passport. If you're traveling as a diplomat it's done on a diplomatic passport, not on your regular passport. They can coexist. The diplomatic passport is part of the job and is cancelled when you're no longer in the job.
3) Because your travel requirements need extra(s):
3a) Visas. You need to travel to country A while your passport is at country B's embassy getting a visa. Realistically, only an issue for heavy travelers.
3b) Naughty lists. You travel to both country A and country B, B prohibits travel by those who have gone to A. Typically, A responds to this by providing visas on a separate piece of paper and not stamping your passport at all, but that's not enough if you travel across a land border from A. The entry stamp from C will out you as having been to A. Israel is the prime example, South Africa used to be and I'm not sure if there are any others at this point.
I believe all such extra passports only have two years of validity.
I've never been in a situation that required an extra passport but we were careful to exclude South African stamps from our passports. Fortunately, while the words "South Africa" were anathema to most African nations they knew the economic reality and ignored things like the border stamps (we had them from both Zimbabwe and Botswana) and packages with labeling in Afrikkans. So long as you blacked out the hated "Product of South Africa" on the label customs would ignore them.
There is also a quasi case 4: Expired passports may still have use. We have valid? (suspended, who knows if they will be reinstated) visas for China in expired passports. Using them requires showing both passports--something that the Chinese authorities seem to have no problem understanding but which others who look at visas seem to not understand very well.
Note that all of these can coexist.