Mafia III

After installing the DLC, you will be notified that Proximity Mines are now available to purchase from the Arms Dealer. You can only carry up to four Proximity Mines at once and they each cost $450.

This achievement is fairly self-explanatory, but the best way to go about getting thirty kills (if you don't have them by the time you complete the DLC) is to visit the police station in the French Ward district. Once there, toss a Screaming Zemi into the garage in order to lure five to six police officers into a tight group. Once they are grouped together, throw a Proximity Mine so that it makes direct impact with one of their bodies. The direct impact will trigger an explosion, resulting in five or six kills! Now you can purposefully get yourself killed and repeat this process over and over again until the achievement unlocks.

NOTE: If following the farming method outlined above, make sure you deposit all your money with your consigliere, otherwise you will lose your funds each time you respawn with money in your wallet.