How Can Detectives Use Black Light to Reveal Hidden Blood Evidence?

  • Thread starter tribdog
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In summary, Luminol is a chemical that glows under a black light if there is blood on the surface. This is useful for crime scenes because it allows investigators to see if there has been a blood massacre.
  • #1
tribdog
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I just watched one of those crime shows on tv. They sprayed a chemical on a wall then turned on a black light and the chemical glowed if there was any blood on the wall. Even if the wall had been wiped clean. From now on everytime I wash my walls I'm going to drip a few drops of blood into my cleaning bucket then if in the future my place becomes a crime scene (which is possible in my neighborhood) if they spray that stuff on my walls it will look like a massacre took place there.
 
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  • #2
Sounds good =) Luminol is actually pretty cool to play around with: the iron in your blood catalyzes its oxidation. I don't actually know what they spray on prior to using the UV light, as I was under the impression that UV-B rays would cause blood to fluoresce, naturally.
 
  • #3
Or you can just drop a lot of blood in the paint.
 
  • #4
If you really want to bug the cops, you'd do this instead (from xkcd):
hobby.jpg
 
  • #5
Poop-Loops said:
Or you can just drop a lot of blood in the paint.

does it even have to be a lot of blood? The way they made it sound on tv just a couple drops should be enough to cover the walls.
 
  • #6
If you are planning to put up wallpaper.
Get some blood (or red paint) and write "I will kill again" in large letters on the wall before covering with wallpaper.
Ok - you don't get to see the punchline when the next owners redecorate, but you can imagine!
 
  • #7
I've got some markers that show up under a black light. I've been writing stuff on walls for years in case the next person who lives there is a stoner. I like to write stuff like "Help Me" and "Let me out" and "I'm watching you"
 
  • #8
Haha, great idea. That would keep them scratching their heads for a while.

On a vaguely related note, I decided a while ago that if I ever kill myself, I'm going to take a small key and a capsule containing a cryptic note (possibly in code) and a map of a fictitious location and swallow them, then top myself in such a way that would require a post mortem. Hopefully the detectives would be puzzling over that for years.
 
  • #9
I'm sure you can get the blood from some animal, but then that would be cruel.
 
  • #10
How about at a slaughterhouse?
 
  • #11
How about that hooker I killed last week?
 
  • #12
JasonRox said:
I'm sure you can get the blood from some animal, but then that would be cruel.

Yeah, cruel to me and my back having to catch them (that's what I spent my morning doing, collecting blood from sheep that behaved more like little bulldozers...they were short, stocky sheep who would get their heads down and just keep going...I wonder if I'm going to be able to stand up straight tomorrow).

I love those detective shows as much for the comedy value as the drama aspect. "I need a DNA analysis in an hour," never mind that you can't actually do it that quickly and that you have no reference sample, afterall, they have that big government database with everyone's genetic fingerprints in it to match it. :rofl:
 
  • #13
I think if you throw bleach over blood it destroys the plasma. They won't be able to extract the dna.
 
  • #14
mgb_phys said:
If you are planning to put up wallpaper.
Get some blood (or red paint) and write "I will kill again" in large letters on the wall before covering with wallpaper.
Ok - you don't get to see the punchline when the next owners redecorate, but you can imagine!

Has to be very tacky wallpaper. To ensure they take it down.
 
  • #15
tribdog said:
How about that hooker I killed last week?

Cyrus said:
I think if you throw bleach over blood it destroys the plasma. They won't be able to extract the dna.

A new business is born. Instant Crime Scene Clean UP open 24/7 free estimates call big AL at 567-888-KILL

There are already companies that do it after the investigations.
 
Last edited:

1. What is the most common type of case that gives detectives nightmares?

The most common type of case that gives detectives nightmares is a cold case - a case that has remained unsolved for a long period of time, often with little to no evidence or leads.

2. What makes a case particularly challenging for detectives?

Cases that involve multiple suspects or complex motives can be particularly challenging for detectives. These cases require a lot of time and resources to thoroughly investigate and may involve sifting through conflicting testimonies and evidence.

3. Are there any specific types of evidence that are more likely to give detectives nightmares?

Yes, DNA evidence can be particularly difficult for detectives to analyze and interpret. This type of evidence is often complex and requires specialized training and equipment to process and analyze.

4. How do detectives cope with the emotional toll of working on difficult cases?

Detectives often have a strong support system, both within their department and with their family and friends. They may also seek therapy or counseling to help them cope with the emotional toll of their work.

5. Can detectives ever truly "solve" a case that gives them nightmares?

While some cases may never be fully solved, detectives work tirelessly to gather as much evidence as possible and bring some closure to the victims and their families. Even if a case remains unsolved, detectives may continue to work on it, hoping for new leads or advancements in technology that may help solve the case in the future.

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