As far as the bounties go, I have never been able to capture a target from one of the daily bounty mission from City Hall alive. I explain that by these being 'kill orders', not 'dead or alive' and the game is simply making that happen for the player. Some of the specific bounties *can* be taken alive, like Tuner, so I don't know if it's intentional or left over from before males were capturable.
I don't know of any renewable source of capturable prowlers.