How to make it so only my player activates Trigger

Ok so I made an AI for a zombie like thing that follows you (currently a cube for testing) and I wrote this script:

 var target : Transform;
 var enemy : Transform;
 var moveSpeed : float = 5.0;
 var inRange : boolean = false;
 
 function Start() {
 moveSpeed = moveSpeed*Time.deltaTime;
 }
 
 function OnTriggerEnter() {
     inRange = true;
 }
 
 function OnTriggerExit() {
     inRange = false;
 }
 
 function Update() {
     if(inRange == true) {
         enemy.transform.LookAt(target);
         enemy.transform.position = Vector3.Lerp(
         enemy.position, target.position,
         Time.deltaTime * moveSpeed);
     }
 }

So the cube follows me but whenever I shoot my gun it just freezes the cube in place. I supposed this was caused by the bullet (currently an invisible sphere) glitching the trigger. Can someone help me find out whats wrong please?

PS this is the gun script:

 var bulletPrefab : Transform;
 var shootSpeed : float = 99999999;
 var clipAmmo = 12;
 var Ammo = 196;
 var ammoLeft : boolean = true;
 var gunShotSFX : AudioSource;
 var noAmmoSFX : AudioSource;
 var reloadSFX : AudioSource;
 
 function Update() {
     if(clipAmmo > 0) {
         if(Input.GetButtonUp("Fire1")) {
             var bullet = Instantiate(bulletPrefab,
         
             GameObject.FindWithTag("BarrelFront").transform.position,
         
             GameObject.FindWithTag("Gun1").transform.rotation);
             
             clipAmmo = clipAmmo - 1;
             
             gunShotSFX.Play();
             
         }
     }
 
 if(ammoLeft == true) {
     if(Input.GetKeyUp("r")) {
         if(clipAmmo == 0) {
             clipAmmo = 12;
             Ammo = Ammo - 12;
             reloadSFX.Play();
         }
         if(clipAmmo == 1) {
             clipAmmo = 12;
             Ammo = Ammo - 11;
             reloadSFX.Play();
         }
         else if(clipAmmo == 2) {
             clipAmmo = 12;
             Ammo = Ammo - 10;
             reloadSFX.Play();
         }
         else if(clipAmmo == 3) {
             clipAmmo = 12;
             Ammo = Ammo - 9;
             reloadSFX.Play();
         }
         else if(clipAmmo == 4) {
             clipAmmo = 12;
             Ammo = Ammo - 8;
             reloadSFX.Play();
         }
         else if(clipAmmo == 5) {
             clipAmmo = 12;
             Ammo = Ammo - 7;
             reloadSFX.Play();
         }
         else if(clipAmmo == 6) {
             clipAmmo = 12;
             Ammo = Ammo - 6;
             reloadSFX.Play();
         }
         else if(clipAmmo == 7) {
             clipAmmo = 12;
             Ammo = Ammo - 5;
             reloadSFX.Play();
         }
         else if(clipAmmo == 8) {
             clipAmmo = 12;
             Ammo = Ammo - 4;
             reloadSFX.Play();
         }
         else if(clipAmmo == 9) {
             clipAmmo = 12;
             Ammo = Ammo - 3;
             reloadSFX.Play();
         }
         else if(clipAmmo == 10) {
             clipAmmo = 12;
             Ammo = Ammo - 2;
             reloadSFX.Play();
         }
         else if(clipAmmo == 11) {
             clipAmmo = 12;
             Ammo = Ammo - 1;
             reloadSFX.Play();
         }
     }
 }
 
     if(0 >= Ammo) {
         ammoLeft = false;
     }
     else if(Ammo > 0) {
         ammoLeft = true;
     }
     
     if(clipAmmo < 1) {
         if(Input.GetButtonUp("Fire1")) {
             noAmmoSFX.Play();
         }
     }
     
 }
 
 function OnGUI() {
     GUI.Box(Rect (10,10,90,25), "Clip: " + clipAmmo);
     GUI.Box(Rect (10,35,90,20), "Ammo: " + Ammo);
 }