A recent addition to the 2.5.2 Dedicated Server which I forgot to add to the Changes List, was that bots can now Pickup & Throw knives. Not all bots though, only bots that have their Primary Weapon set to 'Combat Knife'.
So just create a bot with Combat Knife as their primary, and they will be able to THROW knives at other players, as well as search for knives on the ground (Only when their weapon is Fists).
Enjoy!