Download link: https://www.gta5-mods.com/scripts/locational-damage-deadly-headshots
Locational Damage is a project focused on realism, based on GTA IV armor-health-damage system. As you know, body armors only cover the body, but what happens on GTA V if you get shot, for example, on your leg or your arm? Yeah, your armor decreases, and your health does not change. On GTA IV, if you get shot on your leg, your health decreases even if you have body armor.
The script detects where did you get shot, and if the body part is not the "body" (where your body armor is supposed to be and protect you), it knows how much damage have you received (a.k.a. how much your armor decreased) and puts the armor value to the original one, before getting shot; then, takes that damage and reduces the health.
So, if you have 100% armor and 100% health, when you get shot on your leg, vanilla game decreases armor value. This script decreases health value instead. If you get shot on the body, the armor value will be decreased as usually. If you haven't got armor, the script will change nothing.
Aditionally, Locational Damage features the "deadly headshots" plugin, so if you get shot on your head, you will die instantly! You can enable it on the INI file provided (it's disabled by default).
Future plans include expanding this script and making a complex & realistic health system. Maybe it will be merged with the InjuredRagdoll script on the future.