How would you find which side of a part was touched? [Solved]

I'm making a game where if you shoot a zombie, blue liquid comes out. I have the script for the blaster but, the only thing I'm having trouble on is choosing what direction to point the particle emitter. I want it to go in the direction you shoot the zombie from, but I'm not sure how I would do that.

EDIT: I found out because I was using CFrame, I already made the rotation of the blood source, and I just needed it to be on the "Back" property.

tool = script.Parent
tool.Equipped:connect(function(mouse)
    tool.Activated:connect(function()
        if mouse.Target ~= nil then
            if mouse.Target.Parent:FindFirstChild("Humanoid") then
            plrmodel = mouse.Target.Parent
            mousetarget = mouse.Target
            BloodWeld = Instance.new("WeldConstraint", mouse.Target)
            BloodWeld.Part0 = mouse.Target
            BloodThing = Instance.new("Part", mouse.Target)
            BloodThing.BrickColor = BrickColor.new("Crimson")
            BloodThing.Size = Vector3.new(0.1, 0.1, 0.1)
            BloodThing.Shape = "Ball"
            BloodThing.CFrame = mouse.Hit
            BloodWeld.Part1 = BloodThing
            BloodThing.Anchored = false
            BloodParticles = Instance.new("ParticleEmitter", BloodThing)
            BloodParticles.Size = NumberSequence.new(0.4)
            BloodParticles.Texture = "rbxassetid://44100671"
            BloodParticles.Acceleration = Vector3.new(0, -11, 0)

            BloodParticles.EmissionDirection = "Back"

            BloodParticles.Rate = 20
            BloodParticles.Color = ColorSequence.new(Color3.new(0, 200, 255))
            print(mouse.Target)
            BloodBleed()
            end
            end
end)
end)

function BloodBleed()
    local BloodThingFunction = BloodThing
    for i=1, 100 do
    oof = mousetarget
    wait(0.01)
    health = BloodThingFunction.Parent.Parent.Humanoid.Health
    BloodDrop = Instance.new("Part", oof)
    BloodDrop.BrickColor = BrickColor.new("Deep blue")
    BloodDrop.Size = Vector3.new(0.1, 0.1, 0.1)
    BloodDrop.Position = BloodThingFunction.Position
    BloodThingFunction.Parent.Parent.Humanoid.Health = health-1
    end
    wait()
function getAttachment0(attachmentName)
for _,child in next,plrmodel:GetChildren() do
local attachment = child:FindFirstChild(attachmentName)
if attachment then
return attachment
end
end
end
plrmodel.Humanoid.Died:Connect(function(var)
local removeHRP = true
local head = plrmodel["Head"]
local leftarm = plrmodel["Left Arm"]
local leftleg = plrmodel["Left Leg"]
local rightleg = plrmodel["Right Leg"]
local rightarm = plrmodel["Right Arm"]
local torso = plrmodel.Torso
local root = plrmodel.HumanoidRootPart
if removeHRP == true then
root:Destroy()
end
local rootA =Instance.new("Attachment")
local HeadA = Instance.new("Attachment")
local LeftArmA = Instance.new("Attachment")
local LeftLegA = Instance.new("Attachment")
local RightArmA = Instance.new("Attachment")
local RightLegA = Instance.new("Attachment")
local TorsoA = Instance.new("Attachment")
local TorsoA1 = Instance.new("Attachment")
local TorsoA2 = Instance.new("Attachment")
local TorsoA3 = Instance.new("Attachment")
local TorsoA4 = Instance.new("Attachment")
local TorsoA5 = Instance.new("Attachment")
local function set1()
HeadA.Name = "HeadA"
HeadA.Parent = head
HeadA.Position = Vector3.new(0, -0.5, 0)
HeadA.Rotation = Vector3.new(0, 0, 0)
HeadA.Axis = Vector3.new(1, 0, 0)
HeadA.SecondaryAxis = Vector3.new(0, 1, 0)
LeftArmA.Name = "LeftArmA"
LeftArmA.Parent = leftarm
LeftArmA.Position = Vector3.new(0.5, 1, 0)
LeftArmA.Rotation = Vector3.new(0, 0, 0)
LeftArmA.Axis = Vector3.new(1, 0, 0)
LeftArmA.SecondaryAxis = Vector3.new(0, 1, 0)
LeftLegA.Name = "LeftLegA"
LeftLegA.Parent = leftleg
LeftLegA.Position = Vector3.new(0, 1, 0)
LeftLegA.Rotation = Vector3.new(0, 0, 0)
LeftLegA.Axis = Vector3.new(1, 0, 0)
LeftLegA.SecondaryAxis = Vector3.new(0, 1, 0)
RightArmA.Name = "RightArmA"
RightArmA.Parent = rightarm
RightArmA.Position = Vector3.new(-0.5, 1, 0)
RightArmA.Rotation = Vector3.new(0, 0, 0)
RightArmA.Axis = Vector3.new(1, 0, 0)
RightArmA.SecondaryAxis = Vector3.new(0, 1, 0)
RightLegA.Name = "RightLegA"
RightLegA.Parent = rightleg
RightLegA.Position = Vector3.new(0, 1, 0)
RightLegA.Rotation = Vector3.new(0, 0, 0)
RightLegA.Axis = Vector3.new(1, 0, 0)
RightLegA.SecondaryAxis = Vector3.new(0, 1, 0)
rootA.Name= "rootA"
rootA.Parent = root
rootA.Position = Vector3.new(0, 0, 0)
rootA.Rotation = Vector3.new(0, 90, 0)
rootA.Axis = Vector3.new(0, 0, -1)
rootA.SecondaryAxis = Vector3.new(0, 1, 0)
end
local function set2()
TorsoA.Name = "TorsoA"
TorsoA.Parent = torso
TorsoA.Position = Vector3.new(0.5, -1, 0)
TorsoA.Rotation = Vector3.new(0, 0, 0)
TorsoA.Axis = Vector3.new(1, 0, 0)
TorsoA.SecondaryAxis = Vector3.new(0, 1, 0)
TorsoA1.Name = "TorsoA1"
TorsoA1.Parent = torso
TorsoA1.Position = Vector3.new(-0.5, -1, 0)
TorsoA1.Rotation = Vector3.new(0, 0, 0)
TorsoA1.Axis = Vector3.new(1, 0, 0)
TorsoA1.SecondaryAxis = Vector3.new(0, 1, 0)
TorsoA2.Name = "TorsoA2"
TorsoA2.Parent = torso
TorsoA2.Position = Vector3.new(-1, 1, 0)
TorsoA2.Rotation = Vector3.new(0, 0, 0)
TorsoA2.Axis = Vector3.new(1, 0, 0)
TorsoA2.SecondaryAxis = Vector3.new(0, 1, 0)
TorsoA3.Name = "TorsoA3"
TorsoA3.Parent = torso
TorsoA3.Position = Vector3.new(1, 1, 0)
TorsoA3.Rotation = Vector3.new(0, 0, 0)
TorsoA3.Axis = Vector3.new(1, 0, 0)
TorsoA3.SecondaryAxis = Vector3.new(0, 1, 0)
TorsoA4.Name = "TorsoA4"
TorsoA4.Parent = torso
TorsoA4.Position = Vector3.new(0, 1, 0)
TorsoA4.Rotation = Vector3.new(0, 0, 0)
TorsoA4.Axis = Vector3.new(1, 0, 0)
TorsoA4.SecondaryAxis = Vector3.new(0, 1, 0)
TorsoA5.Name = "TorsoA5"
TorsoA5.Parent = torso
TorsoA5.Position = Vector3.new(0, 0, 0)
TorsoA5.Rotation = Vector3.new(0, 90, 0)
TorsoA5.Axis = Vector3.new(0, 0, -1)
TorsoA5.SecondaryAxis = Vector3.new(0, 1, 0)
end
local function set3()
end
spawn(set1);
spawn(set2);
local HA = Instance.new("HingeConstraint")
HA.Parent = head
HA.Attachment0 = HeadA
HA.Attachment1 = TorsoA4
HA.Enabled = true
HA.LimitsEnabled=true
HA.LowerAngle=0
HA.UpperAngle=0
local LAT = Instance.new("BallSocketConstraint")
LAT.Parent = leftarm
LAT.Attachment0 = LeftArmA
LAT.Attachment1 = TorsoA2
LAT.Enabled = true
LAT.LimitsEnabled=true
LAT.UpperAngle=90
local RAT = Instance.new("BallSocketConstraint")
RAT.Parent = rightarm
RAT.Attachment0 = RightArmA
RAT.Attachment1 = TorsoA3
RAT.Enabled = true
RAT.LimitsEnabled=true
RAT.UpperAngle=90
local HA = Instance.new("BallSocketConstraint")
HA.Parent = head
HA.Attachment0 = HeadA
HA.Attachment1 = TorsoA4
HA.Enabled = true
local TLL = Instance.new("BallSocketConstraint")
TLL.Parent = torso
TLL.Attachment0 = TorsoA1
TLL.Attachment1 = LeftLegA
TLL.Enabled = true
TLL.LimitsEnabled=true
TLL.UpperAngle=90
local TRL = Instance.new("BallSocketConstraint")
TRL.Parent = torso
TRL.Attachment0 = TorsoA
TRL.Attachment1 = RightLegA
TRL.Enabled = true
TRL.LimitsEnabled=true
TRL.UpperAngle=90
local RTA = Instance.new("BallSocketConstraint")
RTA.Parent = root
RTA.Attachment0 = rootA
RTA.Attachment1 = TorsoA5
RTA.Enabled = true
RTA.LimitsEnabled=true
RTA.UpperAngle=0
head.Velocity = head.CFrame.lookVector*30

for _,child in next,plrmodel:GetChildren() do
if child:IsA("Accoutrement") then
for _,part in next,child:GetChildren() do
if part:IsA("BasePart") then
part.Parent = plrmodel
child:remove()
local attachment1 = part:FindFirstChildOfClass("Attachment")
local attachment0 = getAttachment0(attachment1.Name)
if attachment0 and attachment1 then
local constraint = Instance.new("HingeConstraint")
constraint.Attachment0 = attachment0
constraint.Attachment1 = attachment1
constraint.LimitsEnabled = true
constraint.UpperAngle = 0
constraint.LowerAngle = 0
constraint.Parent = plrmodel
end
end
end
end
end
end)
    BloodThingFunction.Parent.Parent:BreakJoints()
    BloodThingFunction:Destroy()
end

The thing I need help on is on line 22. Thanks for any help :)