Porting forensics from Aurora.

code/modules/projectiles/ammunition.dm

@@ -7,6 +7,8 @@
 	slot_flags = SLOT_BELT | SLOT_EARS
 	throwforce = 1
 	w_class = 1
+
+	var/leaves_residue = 1
 	var/caliber = ""					//Which kind of guns it can be loaded into
 	var/projectile_type					//The bullet type to create when New() is called
 	var/obj/item/projectile/BB = null	//The loaded bullet - make it so that the projectiles are created only when needed?

code/modules/projectiles/guns/projectile.dm

@@ -68,6 +68,16 @@
 /obj/item/weapon/gun/projectile/proc/process_chambered()
 	if (!chambered) return
 
+	// Aurora forensics port, gunpowder residue.
+	if(chambered.leaves_residue)
+		var/mob/living/carbon/human/H = loc
+		if(istype(H))
+			if(!H.gloves)
+				H.gunshot_residue = chambered.caliber
+			else
+				var/obj/item/clothing/G = H.gloves
+				G.gunshot_residue = chambered.caliber
+
 	switch(handle_casings)
 		if(EJECT_CASINGS) //eject casing onto ground.
 			chambered.loc = get_turf(src)