Investigating Crime Scenes Edmond Locard and his Principle of Exchange

Dr. Edmond Locard was the director of the world's first forensic lab in Lyon, France. In this capacity, her came up with what we now call Locard's Principle of Exchange. The idea is that whenever a person/place/thing comes in contact with another person/place/thing, there is some exchange of trace evidence. He also noted that the intensity and duration of the contact, and nature of the materials determine the extent of the transfer. For example, if you bump into someone on the sidewalk, there will be less exchange than if you spent four hours in their home.

Lessons from the JonBenet Ramsey Case

JonBenet Ramsey
The 1996 homicide (murder) investigation of six-year-old JonBenet Ramsey provides valuable lessons in proper crime scene investigation procedures. From this case, we learn how important it is to secure a crime scene. Key forensics evidence can be lost forever without a secure crime scene.

In the Ramsey case, the police in Boulder, Colorado, allowed extensive contamination of the crime scene. Police first thought JonBenet had been kidnapped because of a ransom note found by her mother. For this reason, the police did not search the house until seven hours after the family called 911. The first-responding officer was investigating the report of the kidnapping. The officer did not think to open the basement door, and so did not discover the murdered body of the girl.

Believing the crime was a kidnapping, the police blocked off JonBenet's bedroom with yellow and black crime scene tape to preserve evidence her kidnapper may have left behind. They didn't, however, seal off the rest of the house, which was also part of the crime scene. Then the victim's father, John Ramsey, discovered his daughter's body in the basement of the home. He covered her body with a blanket and carried her to the living room. In doing so, he contaminated the crime scene and may have disturbed evidence. That evidence might have identified the killer.

Once the body was found, family, friends, and police officers remained close by. The Ramseys and visitors were allowed to move freely around the house. One friend even helped clean the kitchen, wiping down the counters with a spray cleaner—possibly wiping away evidence. Many hours passed before police blocked off the basement room. A pathologist did not examine the body until more than 19 hours after the crime took place.

Ransom Note
To this day, JonBenet Ramsey's murder remains unsolved.

Your Task

Tell me about mistakes made in the handling of the crime scene in the JonBenet Ramsey case.

IN AT LEAST 1 FULL PARGRAPH of 4-6 sentences (don't number the questions!), answer the following:

What did investigators do wrong in the JonBenet Ramsey case? Consider the 7 Ss of Crime Scene Investigation. Were they all done?
Thinking in terms of Locard's Principle of Exchange (this means you have to talk about Locard's Principle of exchange), how did investigators' action (or lack thereof) influence what trace evidence was available to investigators?

Someone please help me

September 10, 2016: you’ve been assigned to investigate a hit-and-run incident. when you arrive at the scene, it’s raining and foggy. the roads are slick. it looks like the crash occurred during the early evening, about 5: 30 pm, a couple hours before dark. you notice a green 2010 chevrolet camaro lying off the road on an embankment and a blue 2014 toyota camry several yards back. both vehicles are damaged. robert b., the driver of the camaro, had severe back injuries and was taken to the hospital. the only witness is the toyota driver, fred h. fred h. was driving in the right lane when the accident occurred. according to fred, a red ford pickup truck (year and model unknown) suddenly swerved across the highway from the left lane. the pickup truck hit the front left side of the camaro in one of the center lanes, pushing it off the road before speeding away. the camaro lost control and sideswiped the toyota as it skidded across the highway, denting the toyota’s left side panels. the camaro then skidded across the grass to the right of the highway and crashed into a low concrete wall. the hood and both sides of the camaro have extensive damage. the toyota driver pulled up behind the camaro and called the police. the accident occurred near miami, florida, on i-95 northbound, a 5-lane highway. it happened just before the exit 16 offramp. fred h. and robert b. both passed breathalyzer tests. neither had any passengers in the car. as you search the scene, you notice: tire tracks/skid marks left on the pavement deep red scrapes across the camaro’s panels and green scrapes across the toyota’s panels broken car window fragments of a hood or panel a torn rag an empty beer can deep tire marks and footprints in the mud of the embankment at the scene use the information above to answer the following questions. for each of a – e above, give an example of a type of evidence you could collect from that item and how you would collect it. (one to two sentences each) fill out a crash form for the incident. use the form florida crash report and use the information in the description above to create a brief three- to five-sentence summary for the “narrative” section. use the witness’s description to draw a diagram of the incident. if you can’t find a piece of information for the form, just leave that part blank. impression evidence three separate tire marks were collected from the scene. the marks were found in a pattern that supports fred’s version of events. three tire tread marks, a, b, and c. tire a appears to be worn flat in the middle from overinflation, tire b is narrow and appears worn on the outside edges, tire c looks normal and is not worn at all tires leave different types of marks based on their wear patterns. for example, tires that are constantly flat will leave different impressions than tires that are normally inflated or overinflated. the tires tend to wear out on the parts that are most exposed to the road. you checked out the tires of the two vehicles at the scene. here’s what you found: two tires side by side. a camaro tire which appears to be in good shape, and a toyota tire which appears worn on the outside edges the camaro had normal tires, but the toyota’s tires were a little flat and overly worn on the outside edges. the condition of the red ford truck’s tires is unknown. match the three impressions with the cars that most likely created them. what can you hypothesize about the red pickup’s tires? could this have anything to do with the accident? explain your answer. (two to four sentences) a red pickup fitting fred’s description was later seen running a stoplight. police pulled it over for a check. its tire impressions looked like this: a single tire tread mark which appears worn on the outside edges based on the evidence, do you think this was the same red pickup that rammed the camaro? why or why not? (one to two sentences)