Jackvance wrote:
Because it's showing weakness. If you raised all the previous streets, you have basically been saying "I have a good hand" all the time. The other guys don't know what you have. But if you suddenly check.. they might think "hm, less confidence in his hand, maybe he doesn't have anything that strong afterall".
I'd check behind that trips.

Showing weakness by checking behind can be done on flop and turn, sometimes I do it against habitual bluffers or to control the pot size with light hand. On river you just flip over your hand and hope for the best.