Friday, June 26, 2009

The Weather and Animal Helpers

by Andrea Campbell

Some scientists have always thought that weather is often the forgotten factor in crime rates. Is there a relationship between temperature and aggression? Here are some findings, what do you think?

• Assaults are highest in the summer months and lowest in winter months
• Assaults are negatively correlated with wind speed and levels of humidity (most assaults seem to occur on dry days)
• Family disturbances are positively correlated with ozone activity
• Fewer violent crimes are reported on cold days, for example, the crime rate in New Your City was very low during the blizzard of 1996

Some of these may seem intuitive, meaning, people don't function or aren't as aggressive on bad weather days—that's a given. But I do know that law enforcement are especially vigilant on full moons as well, what can be drawn from this conclusion?

Weather and Temperature Clues

Police questioned a man as to where he had been all evening. The man claimed he was home watching TV. One of the officers noted his coat was hanging on a chair dripping from the rain outside. Weather did not help his case. Cases have been recorded where murderers have upped the thermostat before leaving a room to alter the time of death estimation because extreme cold and extreme heat will both alter the coroner’s results. This and other stories illustrate how valuable weather conditions, temperatures, wind speed, sun glare and other phenomenon can effect cases, alibis and time of death estimations.

Animals and Animal Hair

A burglar in southern China was heading into a house to break into a family’s safe inside. The owner, Sham Man-ling, came home and got into a kicking, screaming brawl with him. Mimi, Man-ling’s Persian cat, sprang from a shelf and clawed the robber, who ran away.

Mack, a parrot, was just as courageous. When a criminal tried to steal tools from D’Light, a store in Glendale, California, Mack, who lived at the store, jumped on him, pecked him furiously, and
squawked. In self-defense, the burglar yanked out Mack’s feathers, hit the bird’s head and threw him unconscious to the ground. Still, Mack had detained the burglar long enough for police to respond to the store’s alarm.

In addition to courage, animal hair and feathers have been used as evidence. Dog hair clinging to the suspect’s clothes has been used to identify killers and feathers have shown up in the barrel of a gun. Police also routinely check nests in outdoor scenes because animals are fond of collecting loose artifacts.

Good News for Fingerprint Technology

Technological advances are common in the computing industry and forensic science has benefited from these new advances as well. There is a promising new development for
AFIS (Automated fingerprint identification system). The automation of narrowing the field of candidates for a potential match is getting faster.

Before a latent print can be entered into AFIS, the forensic science fingeprint examiner must carefully mark distinguishing characteristics of the full or partial print.

According to the
National Institute of Standards and Technology (NIST), the manual human process of the mark-up is being automated with something called: Automatic Feature Extraction and Matching (AFEM).

This past April, results of an evaluation where researchers used a data set of 835 latent prints and 100,000 fingerprints from real cases was tested. The AFEM software extracted distinguishing features of latents and compared them against the 100,000 fingerprints. For each print, software gave up a list of 50 candidates that the fingerprint specialist had compared by hand. Most identities were found in the top ten.

For more information about the companies that participated and the results of the test:


FleaStiff said...

The automation of his segment of the fingrpint process is welcomed since the human performance of it is so variable with re-submittal of a print often leading to opposite conclusions.

Recent advance in lifting prints from spent catridges even those hat have been washed or wiped down is likely to mean greater activity on cold cases.

FleaStiff said...

"Not only some, but most, of the fingerprint examiners changed their minds (when re-submitted prints were accompanied by subjective information about the case)".

FleaStiff said...

Given the McKie/Ross fiasco exposing incompetence and a vindictive campaign of intimidation against a wronged police detective, it is perhaps best that the process be as automated as possible. To this day the Scottish fingerprint experts maintain ALL the foreign experts are wrong.

Andrea Campbell said...

Dear Fleastiff,

Thank you for leaving such cogent comments.

I went to a workshop not long ago where we were able to photograph prints on cartridges. We managed to enhance them using bluing—the type of dye used for bluejeans—and it worked great.

Come back and leave remarks anytime, I love it.

Andrea Campbell said...


The automation of fingerprints will be a godsend for the courts and there are some top companies working on the process.

FleaStiff said...

Concerning crime and the full moon: statisticians tell us 'no' its simply more relevant to look at paynights and alcohol sale, but most ERs still dread a full moon, particularly on hot summer night.