NEED HELP WITH ENEMY AI SCRIPT

Just a little note, using Vector3.Distance for checking distance means you are performing the check on each frame. You could actually get rid of this calculation using a trigger.

Add a sphere collider to your cop and add a wanted boolean to your player that is set to true when he shoots in the street or beat up/kill someone

 var target :PlayerScript;
 var chase :boolean;
 
 function Start(){
    target = GameObject.Find("Player").GetComponent(PlayerScript);
 }
 
 function OnTriggerEnter(other:Collider){
    if(other.gameObject.tag=="Player" &&  target.wanted)
       chase = true;
 }

Now you are only checking if the boolean is true.

 function Update(){
    if(chase){
       //everything else
    }
 }

This might help you, you are missing the functions, this is a script I used a while ago with just a cube to do some testing.

 var attackSpeed = 3.0;
 var dampingLook = 6.0;
 var dampingRun = 1.0;
 var startOfRun : Transform;
 var endOfRun : Transform;
 var speedToRun = 1.0;
 var CatSound : AudioClip;
 var catAnimateCntrl : AnimationControllerCat; // Set link to my AnimationControllerCat script that is attached to the Cat
 
 private var isColliding : boolean;
     
 function Awake()
 {
  if(!Target)
  {
  Target = GameObject.FindWithTag("Player").transform; 
  }
 }
 
 function Update()
 {
  distance = Vector3.Distance(Target.position, transform.position);
  
  if(canAtackTarget())
  {
  var targetRotation = Quaternion.LookRotation(Target.position - transform.position, Vector3.up);
  transform.rotation = Quaternion.Slerp(transform.rotation, targetRotation, Time.deltaTime * dampingLook);
  }
  
  // runs away 
  if (isColliding == true)
  {
  catRunOff();
  }
 }
 
 function canAtackTarget()
 {
  if(distance > lookAtDistance)
  {
  renderer.material.color = Color.green;
  //print("Out of range");
  return false;
  }
  
  if(distance < attackRange)
  {
  renderer.material.color = Color.red;
  //print("Attacking");
  attack();
  return true;
  }
  
  var seeYou : RaycastHit;
  
  // Check to see if there is anything between Cat and Mouse
  if(Physics.Linecast(transform.position, Target.position, seeYou))
  {
  if(seeYou.collider.gameObject.tag != "Player")
  {
  //print("Can not see you " + seeYou.collider.gameObject.name + " in the way");
  renderer.material.color = Color.green;
  return false;
  }
  else
  {
  //Player ditected
  renderer.material.color = Color.yellow;
  catAnimateCntrl.Idel();
  return true;
  }
  }
  return true;
 }
 
 function lookAt()
 {
 var rotation = Quaternion.LookRotation(Target.position - transform.position, Vector3.up);
 transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * dampingLook);
 animation.CrossFade("Idel",0.2); // Play the Idel animation
 }
 
 function attack()
 {
  // The Vector3 0.2 stops the object going into the floor
     transform.Translate(Vector3(0, 0.2, 1) * attackSpeed *Time.deltaTime);
     catAnimateCntrl.Walk();
 }
 
 // rotate Cat to look at waypoint and run off
 function catRunOff()
 {
  var rotation = Quaternion.LookRotation(endOfRun.position - transform.position, Vector3.up);
  transform.rotation = Quaternion.Slerp(transform.rotation, rotation, Time.deltaTime * dampingRun);
  catAnimateCntrl.Run();
  transform.position = Vector3.Lerp(startOfRun.position, endOfRun.position, attackSpeed / 250);
 }
 
 // Check if cat and mouse collide
 function OnCollisionEnter(theCollision : Collision)
 { 
  if((theCollision.gameObject.name == "Player") || (theCollision.gameObject.name == "Weapon"))
  {
  isColliding = true;
  audio.pitch = Random.Range(0.8f, 1.0f);
  audio.PlayOneShot(CatSound);
  return;
  }else{
  isColliding = false;
  }
 }