Your Stun Gun is Very Versatile
The first weapon granted to you in Watch Dogs 2, aside from your melee weapon, is the Stun Gun. A non-lethal gun that doesn’t have the greatest range, but can quickly put a nosy guard to sleep if you find yourself being approached or just want to clear out the ranks. You can upgrade it for more range and faster reload, but that still doesn’t make it the greatest weapon from a straight up offensive standpoint. However, it has more uses than just putting people to sleep.
There is a hack you can get later in the game that allows you to turn off security devices. It costs a lot of skill points and you need a specific piece of Key Data as well, which you may not want to stop and collect. It turns out that the stun gun can also turn of security devices for approximately 10 seconds, giving you time to sneak by and get into places. It saves you the skill points and keeps you from getting into trouble. Not too shabby, huh?