How did these two sentences "I am looking for a responsible man" and "I am looking for the man responsible" come to take on different meanings?

The first sentence "I am looking for a responsible man" means that I am looking for someone who can be trusted whereas the second sentence "I am looking for the man responsible" means that I am looking for the man who has done something.

In the former, responsible acts as a prepositive adjective while in the latter a postpositive adjective.

What are the perhaps etymological or linguistic reasons that led to these two sentences with the main word ‘responsible’ take on different meanings?