Crime Scene Investigation – Who does What?

Crime Scene Investigation


Uniformed officers are normally the first police officers on the scene. It’s up to these front-line cops to take charge, calm the chaos, and make things safe for the arriving investigators. Sometimes, crime scenes are large and complicated; therefore, it may be necessary to set up a command post – a central location for coordinating police activities.

Many police departments use mobile command centers, such as converted motor homes and travel trailers. Some patrol supervisors drive vehicles designed to quickly transform into a fully functional command post.

This Oregon police sergeant drives a marked SUV that also serves as a command post during emergencies and crime scene investigations.

Crime Scene Investigation facts:

Patrol officers often assist police investigators with the recovery and collection of evidence.

Not all crime scene investigators are sworn police officers. Many police departments employ specially trained civilian crime scene investigators/technicians. These crime scene investigators do not:

(As seen on TV)

arrest criminals

interrogate or question suspects

carry weapons

participate in, or conduct autopsies

drive Hummers

All police officers are trained to properly collect and preserve evidence. Sometimes, detectives are unavailable; therefore, uniformed officers assume the duty of investigating the crime.


detective and patrol officer bagging a gun at a crime scene

Ohio police sergeant assists a detective with the collection of a firearm.

Crime scenes may be as small as a single room and they can be as large as the site of the entire area encompassing the collapsed World Trade Center towers.

The police are in charge of crime scenes. Coroners and medical examiners are in charge of the bodies of murder victims.

Next – Crime Scene Evidence


15 replies
  1. l.c.mccabe
    l.c.mccabe says:

    None my friend. My conscience is clear.

    The word uniform is fine. The word uniformed is the problem.

    For some reason my subconscious mind adds the letter “n” in there.

    Every Time.

    It’s a stumbling block for me, I tell ya.

    And my hubby shares the same problem. Just thought you ought to know.

  2. Lee Lofland
    Lee Lofland says:

    Perhaps, there’s a subconscious reason that makes you guys think cops in uniform are uninformed. Just how many unpaid parking tickets do you have, anyway?

  3. l.c.mccabe
    l.c.mccabe says:


    The beginning of this post included the words “uniformed officers” which for some reason gives me and my husband fits.

    It is a perfectly normal and logical phrase, but for some reason our eyes want to add another letter to the word uniformed and then the meaning is drastically changed.

    Maybe it is because we are so used to the word uniform as being a noun and we aren’t accustomed to seeing it made into an adjective.

    Because both of us will read uniformed officers and our brains translates it to uninformed officers.

    :shrugs: I swear I stumble over that combination of words every time.


  4. Terry
    Terry says:

    I’ll tell you, when we went to SleuthFest and they had Miami ME’s and the like as speakers, my husband was CRUSHED to see what they really wear to work. This even though we lived in Miami for 13 years and NOBODY dresses the way the CSIs do — but he watches for the neat animated graphics of the forensiscs stuff and the cleavage. I’m not going to say which he pays more attention to. He sometimes reads this blog.

  5. Joyce Tremel
    Joyce Tremel says:

    Lee said, “There would be no animosity…” I agree. In the almost ten years I’ve worked for a PD, I’ve never seen any animosity between departments. They rely on each other to get the job done. Our dept. assists the smaller, neighboring depts. all the time. Cops are usually grateful for whatever help they can get.

  6. Auntieamy71
    Auntieamy71 says:

    You mean that not all crime scene investigators drives Hummers? I’m shocked, just shocked that what I see on TV is not what it’s like in the real world! Darn! There went the idea for that job!

    Love your blog, it is wonderful. Thank you so much for sharing your expertise with the rest of us.

  7. Lee Lofland
    Lee Lofland says:

    Thanks for your kind comment.

    You’ve touched on another common misconception about police departments. There would be no animosity when a sheriff’s office has been summoned to assist a small town with a case because it would be the police department that called them.

    There’s no secret committee that decides when to override a local department. Besides, a county sheriff has jurisdiction in every town and city within her county, anyway. So does the state police, the FBI, ATF, DEA…

  8. mnboater
    mnboater says:

    You’re doing a great service to enlighten about the truth in crime investigation!

    Curious what the reality is about how other departments are received if the sheriff or the state is called in. Are other departments received well by the local department typically or is there a certain bit of animosity with someone else on their investigation?

  9. Terry
    Terry says:

    The tricky part as a writer is dealing with the reader’s assumption that if they see it on TV, then that’s the way it is, and if you say something different, then you’re the one who’s wrong.

    The very first editor I met warned me about making sure I explained everything my cop did if it wasn’t what readers would expect.

  10. Lee Lofland
    Lee Lofland says:

    Joyce – Many people don’t realize there departments out there that do not have a team of crime scene investigators. In those departments, detectives handle the entire investigation. And, there are lots of police departments in this country that don’t have detectives at all. Patrol officers usually take care of their investigations. They also call on the local sheriff’s office and state police to assist when necessary.

  11. Joyce Tremel
    Joyce Tremel says:

    Our department only has two detectives and no CSI type people, so our patrol officers assist all the time. I, the lowly police secretary, even helped once at a burglary. Okay, I just handed things to the detective. And it was my brother-in-law’s house.

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