Forensics fixes/tweaks.

code/game/atoms.dm

@@ -421,7 +421,6 @@ its easier to just keep the beam vertical.
 		blood_DNA = null
 		return 1
 
-
 /atom/proc/get_global_map_pos()
 	if(!islist(global_map) || isemptylist(global_map)) return
 	var/cur_x = null

code/game/objects/effects/decals/Cleanable/humans.dm

@@ -34,6 +34,7 @@ var/global/list/image/splatter_cache=list()
 		invisibility = 100
 		amount = 0
 		processing_objects -= src
+	..(ignore=1)
 
 /obj/effect/decal/cleanable/blood/Destroy()
 	for(var/datum/disease/D in viruses)

code/game/objects/effects/decals/Cleanable/tracks.dm

@@ -121,7 +121,8 @@ var/global/list/image/fluidtrack_cache=list()
 				updated=1
 
 		dirs |= comingdir|realgoing
-		blood_DNA |= DNA.Copy()
+		if(islist(blood_DNA))
+			blood_DNA |= DNA.Copy()
 		if(updated)
 			update_icon()
 

code/game/objects/effects/decals/cleanable.dm

@@ -1,8 +1,11 @@
 /obj/effect/decal/cleanable
 	var/list/random_icon_states = list()
 
-/obj/effect/decal/cleanable/clean_blood()
-	qdel(src)
+/obj/effect/decal/cleanable/clean_blood(var/ignore = 0)
+	if(!ignore)
+		qdel(src)
+		return
+	..()
 
 /obj/effect/decal/cleanable/New()
 	if (random_icon_states && length(src.random_icon_states) > 0)

code/game/turfs/simulated.dm

@@ -16,8 +16,8 @@
 
 /turf/simulated/clean_blood()
 	for(var/obj/effect/decal/cleanable/blood/B in contents)
-		B.fluorescent = 0
-		B.invisibility = 100
+		B.clean_blood()
+	..()
 
 /turf/simulated/New()
 	..()
@@ -122,6 +122,8 @@
 
 	if(istype(M))
 		for(var/obj/effect/decal/cleanable/blood/B in contents)
+			if(!B.blood_DNA)
+				B.blood_DNA = list()
 			if(!B.blood_DNA[M.dna.unique_enzymes])
 				B.blood_DNA[M.dna.unique_enzymes] = M.dna.b_type
 				B.virus2 = virus_copylist(M.virus2)

code/modules/detectivework/microscope/microscope.dm

@@ -89,18 +89,26 @@
 			user << report.info
 	return
 
-/obj/machinery/microscope/AltClick()
-	if(usr.lying || !Adjacent(usr) || !ishuman(usr))
+/obj/machinery/microscope/proc/remove_sample(var/mob/living/remover)
+	if(!istype(remover) || remover.incapacitated() || !Adjacent(remover))
 		return ..()
 	if(!sample)
-		usr << "<span class='warning'>\The [src] does not have a sample in it.</span>"
+		remover << "<span class='warning'>\The [src] does not have a sample in it.</span>"
 		return
-	usr << "<span class='notice'>You remove \the [sample] from \the [src].</span>"
+	remover << "<span class='notice'>You remove \the [sample] from \the [src].</span>"
 	sample.forceMove(get_turf(src))
-	usr.put_in_hands(sample)
+	remover.put_in_hands(sample)
 	sample = null
 	update_icon()
-	return
+
+/obj/machinery/microscope/AltClick()
+	remove_sample(usr)
+
+/obj/machinery/microscope/MouseDrop(var/atom/other)
+	if(usr == other)
+		remove_sample(usr)
+	else
+		return ..()
 
 /obj/machinery/microscope/update_icon()
 	icon_state = "microscope"

code/modules/detectivework/tools/swabs.dm

@@ -15,30 +15,30 @@
 		return ..()
 
 	if(is_used())
-		return 0
+		return
 
 	var/mob/living/carbon/human/H = M
 	var/sample_type
 
 	if(H.wear_mask)
 		user << "<span class='warning'>\The [H] is wearing a mask.</span>"
-		return 1
+		return
 
 	if(!H.dna || !H.dna.unique_enzymes)
 		user << "<span class='warning'>They don't seem to have DNA!</span>"
-		return 1
+		return
 
 	if(user != H && H.a_intent != "help" && !H.lying)
 		user.visible_message("<span class='danger'>\The [user] tries to take a swab sample from \the [H], but they move away.</span>")
-		return 1
+		return
 
 	if(user.zone_sel.selecting == "mouth")
 		if(!H.organs_by_name["head"])
 			user << "<span class='warning'>They don't have a head.</span>"
-			return 1
+			return
 		if(!H.check_has_mouth())
 			user << "<span class='warning'>They don't have a mouth.</span>"
-			return 1
+			return
 		user.visible_message("[user] swabs \the [H]'s mouth for a saliva sample.")
 		dna = list(H.dna.unique_enzymes)
 		sample_type = "DNA"
@@ -54,24 +54,21 @@
 				has_hand = 1
 		if(!has_hand)
 			user << "<span class='warning'>They don't have any hands.</span>"
-			return 1
+			return
 		user.visible_message("[user] swabs [H]'s palm for a sample.")
 		sample_type = "GSR"
 		gsr = H.gunshot_residue
 	else
-		return 0
+		return
 
 	if(sample_type)
-		used = 1
-		name = "[initial(name)] ([sample_type] - [H])"
-		desc = "[initial(desc)] The label on the vial reads 'Sample of [sample_type] from [H].'."
-		icon_state = "swab_used"
-		return 1
-	return 0
+		set_used(sample_type, H)
+		return
+	return 1
 
 /obj/item/weapon/forensics/swab/afterattack(var/atom/A, var/mob/user, var/proximity)
 
-	if(!proximity || istype(A, /obj/item/weapon/forensics/slide))
+	if(!proximity || istype(A, /obj/item/weapon/forensics/slide) || istype(A, /obj/machinery/dnaforensics))
 		return
 
 	if(is_used())
@@ -103,6 +100,7 @@
 		if(!A.blood_DNA || !A.blood_DNA.len) return
 		dna = A.blood_DNA.Copy()
 		sample_type = "blood"
+
 	else if(choice == "Gunshot Residue")
 		var/obj/item/clothing/B = A
 		if(!istype(B) || !B.gunshot_residue)
@@ -113,7 +111,10 @@
 
 	if(sample_type)
 		user.visible_message("\The [user] swabs \the [A] for a sample.", "You swab \the [A] for a sample.")
-		name = "[initial(name)] ([sample_type] - [A])"
-		desc = "[initial(desc)] The label on the vial reads 'Sample of [sample_type] from [A].'."
-		icon_state = "swab_used"
+		set_used(sample_type, A)
 
+/obj/item/weapon/forensics/swab/proc/set_used(var/sample_str, var/atom/source)
+	name = "[initial(name)] ([sample_str] - [source])"
+	desc = "[initial(desc)] The label on the vial reads 'Sample of [sample_str] from [source].'."
+	icon_state = "swab_used"
+	used = 1