The first police officer that arrives at a crime scene is the often the driving force behind a successful crime scene investigation.  The crime scene locale is where most of the physical evidence associated with the crime is obtained.  Evidence is located, documented, and collected. 

The MOST important task for the police officer first at a scene is to prevent the destruction or diminished value of potential evidence.  This evidence will (hopefully) lead to the apprehension of the criminal responsible for the crime.  Police departments should have policies and procedures for their officers. 

 I can’t stress the importance of the first officer at any crime scene.  The officer should record the time and enter the crime scene properly.  They should quickly assess the overall scene and proceed with extreme caution.  The officer’s notes should include anything about doors, windows, lights, shades, odors, signs of activity, and anything that quickly depicts the scene. 

The most important task for the first officer on the scene is to protect the integrity at the scene.  That means ANYONE not directly related to the investigation should not be allowed to enter the area.  Ever.  The perimeter should be cordoned off with crime scene tape, rope, or barricades.  Anyone coming or going should be documented on a list.  Evidence should be untouched and left for crime scene technicians or investigators.

While waiting for the investigating team to arrive, the first officer should always:

• Write down names of witnesses and anyone else at the scene.
• Note who was at the scene when the officer arrived.
• Establish the basic facts.
• Keep ALL suspects and witnesses separated.
• Instruct the witnesses not to discuss the events or compare notes.
• Do not discuss the crime scene with witnesses or bystanders.
• Listen – sometimes an officer can pick up subtle clues by being a good listener.

Protect evidence that might be in danger of being destroyed (weather poses a big problem for crime scenes).  Sometimes, it’s important to expand the crime scene area as an added precaution.