Who Invented Crime Scene Tape?

Recently Darling Hubby and I were watching one of the many true crime documentaries.

I said, "I wonder who invented crime scene tape."

What I Learned

The official name for what we call crime scene tape is "non-adhesive barricade tape" which is a mouthful.

The yellow tape used by law enforcement was developed in the early 1960s by Harris Industries, a California company, and it's made of lightweight polyethylene.

The standard roll is 3 inches x 1,000 feet, and comes in a variety of thicknesses. The tape can be tied, stapled or nailed in place and is used, according to the manufacturer, to increase visibility of hazards.

Locard's Theory of Transfer

If you've watched very many police procedural or forensics series or movies, you know the tape is designed to keep people who aren't part of the investigating team away from the crime scene.

They want as little interaction with the crime scene as possible because Locard's Theory of Transfer asserts that people entering a crime scene leave behind evidence—from their shoes, clothes, body, and even their breath—and take evidence with them, i.e. stepping on a hair that may have belonged to the killer with the hair adhering to the sole of a shoe.

The more people entering a crime scene, the more it is contaminated. In some states, police arrest anyone crossing crime-scene tape, and the penalty can be jail time.

Why Yellow? Why Not Red or White?

The scientific explanation is that bright yellow is the most eye-catching color because of the way light bounces off the eye’s rods and cones. That makes it easier for it to be perceived more quickly than other colors.

The bright yellow can also be seen by color-blind people whereas red would not. 

Over the years, people have come to associate yellow with caution signs and other hazards. I did not know that school buses are painted yellow because of this. (In 1939, Frank W. Cyr, a professor of education, convinced education leaders to standardize school bus appearance by painting them all a high-visibility yellow.)

Takeaway Truth

You can file this under: "Learn something new every day."

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