I do this a lot as well.

I mark someone as being capable of attacking weakness and stealing. Then I put money in, then check and give him an opportunity to steal - and then I see myself making hero calls.

I've seen a few observations that relate and that I need to remember more when I play:
1) Some people are perfectly happy to bluff a huge range when first in one any street - but will never never bluff raise.
2) Some people are perfectly happy to bluff when the pot is small/medium sized but will never never bluff into a big pot

When I don't have a solid read but a few stats to go buy and I try to determine whether an opponent is likely to be bluffing this river I check his overall aggression in relation to his street by street aggression - if his aggression increases street by street he's more likely bluffing on later streets. If his vpip is huge but his aggression is modest that can still be a big range with bluffs in it. If his won at showdown is very low he might bluff rivers a lot. If his river bet % is high he is likely to bluff rivers a lot.

But yeah, often enough when I make that call I don't have a clear idea if I'm +EV and typically that makes it a losing play.