CSI Evidence Evaluation of the Grapefruit Crime Scene

Agents:Peter UdallCole Tyson

Jennifer ShenJoanna Tolentino

Physical Properties

Definition: Physical properties are properties of matter that can be judged by observing the

matter or it’s measurements.

Examples of Physical Properties

o Density: The amount of mass in a certain amount of space.

o Volume: The amount of three-dimensional space in an enclosed area.

o Ductility: The ability of a substance to stretch into a wire and retain it’s position.

o Malleability: the ability of a substance to be pressed into sheets.

o Magnetism: The ability of a substance to conduct with magnets.

o Color: The pigment of an object

Chemical Properties

Definition: Properties that are only observable during chemical reactions.

Examples of Chemical Properties

o Oxidation: The ability of a substance to react with oxygen.

o Corrosion: The breaking down of a substance based on it’s chemical surroundings.

o Flammability: The ability of a substance to burn

Metal Evaluation

Metal Sample 2

Metal Sample 1

Metal EvaluationMetal Sample 1 Metal Sample 2

http://terpconnect.umd.edu/~wbreslyn/magnets/is-aluminium-magnetic.html

Metal Evaluation

SteelAluminum

Metal Sample 1

• Non-magnetic• Silver in color• Mass: 1.6g• Volume: .5 cm3• Density: 2.7 g/cm3

Metal Sample 2

• Dark grey• Magnetic• Mass 2.6g• Volume .25cm3• Density: 7.85g/cm3

http://terpconnect.umd.edu/~wbreslyn/magnets/is-aluminium-magnetic.html

Conclusion

• Metal sample 1 is aluminum• Metal sample 2 is steel

Liquid Evaluation

• The liquid was either water, liquid, or alcohol

Alcohol

Vinegar

Water

Mystery liquid

Conclusion

• The liquid is rubbing alcohol.

Powder EvaluationH20 Vinegar Iodine

Baking Powder

• Soluble• Milky

substance

• Bubbles up

• Turns black• Absorbent

Baking Soda • Highly soluble

• Turns Cold

• Bubble/explode

• Stayed brown

• Absorbent

Corn Starch • Low solubility• H20 slides off

• No bubbles

• Turned black• Absorbent

Baby Powder • Hydrophobic • Not soluble

• No bubbles

• Every low solubility

• Slides off stays brown

Mystery Powder

• Soluble • Milky

substance

• Bubbles up

• Turns black• absorbent

Baking Powder

Baking Soda

Corn Starch

Baby Powder

Mystery Powder

Mystery powder comparison

Powder conclusion

The powder was baking powder because when it was exposed to vinegar it had the same reaction as the baking powder, and when exposed to iodine it turned black like the baking powder.