Trace Evidence: Powder
By Saige Holst, Ian Lynch, Matti Tuomela, Surabhi Todi
Physical Properties: 3 types of Powder
A white or black color
It is odorless
Has a melting point of 334c
A boiling point of 400c
It has a high thermal conductivity
Common density is 2.109g or 3cm
A white color with no odor
A grainy salt like texture
Melting point of 98c or 208f
Boiling point of 187c or 369f
Bleached flour is artificially aged using a bleaching agent, a maturing agent, or both. A bleaching agent would affect only the carotids in the flour; a maturing agent affects gluten development.
A white color
A smooth texture but low density making it easier to stay on clothing or skin
An odorless substance
Chemical Properies: 3 types of powder
Made up of Potassium nitrate, Sulfur, and Charcoal a formula of KNO3
It is an insoluble substance
Chemical structure of Sulfur and charcoal acts like fuel, while potassium nitrate acts like an oxidizer.
It is also Flammable
Ingredients consist of Oils extracted from the Coca Plant, Analgesic drugs, Vitamin C, Talcum powder, Cornstarch, and Powdered milk the formula is C17H21N04
An Insoluble substance
A Schedule II drug
Chemical structure consists of the base form of cocaine can be smoked, injected, or snorted. Cocaine is considered to be effective for anesthetic use for medical treatment. This stimulant drug is addicting that causes harm to the body.
It is Flammible
Ingredients are Wheat Grains (Gluten), Salt, and Water; with a formula of C6H1005
A soluble substance
Chemical structure is Mixture of grains, salt, and water produce cooking products like bread and cake.
It is not flammable
Forensic Processes and Experts for Powders
For cocaine first thing a forensic scientist does is a screening or presumptive test. There they confirm that the drug may be present. He basically compares the sample to a sample of cocaine.
After that is a confirmatory test where the drug is confirmed to be present.
In the test the drug is put into a spectrometer, that will check the interaction of electromagnetic radiation with matter.
They will probably also put it through a spectro photometry that will send an IR light through the substance and compares it before and after that.
- information from schoology
When a gun is shot, there will be a residue from the gun powder. If the bullet was fired only a few feet away from the target, the forensic scientist is able to determine the exact distance by looking at the diameter of the residue on the target. Residue can also be found from the shooters hand.
The gunpowder will be collected with a swab and then then examined. By detecting the elements of the gunpowder with a mass spectrometer a scientist can trace for example what kind of bullets were used and who was the producer.
If there was white powder found from the crime scene, the forensic scientist would do a presumptive test on the flour and notice that the sample wasn't a drug. Then he should realize that it was flour and after that he would put it into a spectro photometry and compare the test results with a sample of flour to confirm this hypothesis.
The Phil Spector
On February 3, 2003, a young actress Lana Clarkson was found shot in the mouth with a .32 caliber in Phil Spector’s mansion in Los Angeles. He was a famous recording artist in the 1960’s.
Mr. Spector claimed he heard the shot at 5 in the morning and ran down to find she had shot herself. Further inspection showed that there was a struggle. Her wrist was bruised and she had defensive wounds on her body. Blood spatter also indicated someone was standing in front of her when she was shot. Blood was found on Phil Spector's clothing, and gun residue was found on his hands.
The trials lasted 6 years even though the evidence found on Phil Spector was very clear, the other evidence such as blood spatter was messy. The scene had been processed unprofessionally with things getting lost and the body being moved before the scene was photographed and effecting the rigamortis of the body.But 6 years later, he was sentenced to 19 years in jail.
The gun powder residue was one of the few pieces of evidence that was not tampered with or messed up in the case. It helped make the lose case more solidified so that Mr. Spector could be convicted
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Firearms Interpretation — All about ballistics in solving crimes, by Katherine Ramsland — Crime Library Article Title: Ballistics: The Science of Guns Date Accessed: February 05, 2014