Forensic science in criminal justice system Summary

Prepare a detailed press release outlining the benefits of forensic science in the criminal justice system. The aim of the Forensic Science Service (FSS) is to provide forensic science information in the detection of crimes and the prosecution of offenders. The FSS offers services which are an integral part of the criminal justice system. The services provided by the FSS to help the police in their investigations include fibre analysis, DNA profiling, footwear marks, chemical analysis, blood patterns and many more.

Criminal cases hang on forensic evidence, even the smallest of evidence such as fibres left at the crime scene can be most vital in solving a case and prosecuting an offender. Today it is difficult to secure a conviction without forensic evidence to prove the offenders guilt. Fibre analysis by the FSS was vital in securing the arrest and subsequent conviction of Roy Whiting. Whiting was found guilty of the murder and kidnapping of Sarah Payne1 following forensic evidence of fibres and a single hair.

The first link between Whiting and Payne was made when 350 fibres were taken from the Velcro strap on Sarah's shoe using a low-powered microscope. Four of the fibres were matched to Whiting's red sweatshirt using a high-powered microscope. This technique was used to identify the shoe as Sarah's – the blue polyester and cotton fibres found on the shoe matched her school sweatshirt. Identification of Sarah's badly decomposed body was done via DNA profiling using muscle from the body which provided a full DNA profile and matched to a full profile obtained from a milk tooth saved by Sarah's mother.

In 2001/2 DNA profiling was used in approximately 1/2 of all cases compared to 1/4 in 1997/8. 2 In the case of Marion Crofts,3 FSS scientists played a crucial role in helping police find her attacker 20 years later. Scientists, knowing that DNA profiling techniques were rapidly advancing, left a laboratory microscope slide containing samples from Marion's body untouched until such a time when they could unlock the secrets of her death.

The scientists used DNA Low Copy Number (DNA LCN) to obtain a DNA profile and checked it against the National DNA Database (NDNAD) until they got a match, which led to the subsequent conviction of Tony Jasinskyj. This case highlights the value of the NDNAD which is growing all the time making it quicker and more cost-effective to match a DNA profile. The turn around times of DNA criminal justice samples is now 5 days compared to 350 days in March 1997. 4 With the everyday advancements of forensic science 5 days will be reduced to crime scene testing giving an all most immediate result.

An example of advancements in DNA profiling helping to convict criminals is that of 'Operation Phoenix'5, where forensic work by the FSS helped the police to get a conviction from their re-investigation of more than 200 sex crimes between the period of 1985 – 1999. The Project used DNA techniques such as FSS SGM Plus(tm) and DNA LCN, which weren't available at the time to produce DNA profiles. The FSS used FSS SGM Plus(tm) to re-analyse extracts from the original swabs taken from the rape victim. From a mixed profile obtained a major component of the profile was matched to that of Mark Wilkinson on the NDNAD.

There is at present a 40% success rate of matching DNA clues from crime scenes to samples on the NDNAD. 6 Results show that repeat offenders are being identified more easily and now being placed before the courts since DNA LCN was developed. 7 Forensic evidence in criminal cases does not only prove a person's guilt it also proves a persons innocence as was the case in the Sandra Poole case. 8 Jules Cain – Sandra's boyfriend – was framed by his friend Janani Frenziedly – who raped and murdered Sandra – by smearing Cain's initials on the carpet in toothpaste.

During the police investigation Dr McClelland helped the police to analyse the phone call made by Frenziedly, who impersonated a woman. Her knowledge of how ethnicity determines pitch and range of voice, and how younger people say statements like asking questions (Australian question intonation) put the police on the trail of the killers identity. This along with DNA evidence proved that Cain was not Sandra's murderer but Frenziedly was. The work done by forensic scientists does not only convict the common criminal it plays a vital role in helping the police get a conviction in cases such as fraud.

In the 'Art of Deception'9 the analysis of paint samples, using was vital in proving a collection of paintings were forgeries. Study of the paintings showed that they had been painted from the same palette, as the red paint was not fully mixed and this was visible in both paintings. The results from a chemical analysis of the paint using Gas Chromatography showed the presence of a chemical which was not available when the paintings were supposedly painting – proving they were fakes.

Forensic scientists analyse paint samples using Gas Chromatography, to determine the chemical properties of the paint and identify the paint and possibly the manufacturer. In the case of 'The Fox'10 paint fragments were found on a branch of a tree near one of the crime scenes. Forensic scientists matched the paint shade to the manufacturer using the results from the Gas Chromatography. With the knowledge of the manufacturer of the car and the measurements taken from the disturbances in the trees at the crime scene the forensic scientists were able to identify the model of car – leading the police in the direction of the offender.

The details of the car, analysed fibres – rabbit hair from the lining of a pair of gloves – and unusual footwear marks – once analysed using a modified version of Electrostatic Detection Apparatus (ESDA) gave a probable make and size of shoe – gave the police sufficient evidence in order to secure a conviction. Forensic evidence can be used to disprove a persons' statement by analysing and piecing together the chain of events. In the Billie-Jo Jenkins case11 her foster father, Sion Jenkins, said he found Billie-Jo after she had fallen and that the blood on his clothes was from her breathing out.

The blood pattern of about 140 microscopic blood spots disproved his statement. The pattern was "consistent with the defendant having stood very close to Billie-Jo when she was being struck. "12 This view was supported by the fact that similar forensic evidence was not present on the neighbour or ambulance-men who attended the scene of the attack. Sion Jenkins was subsequently convicted of Billie-Jo's murder. Forensic evidence as produced by the FSS is used to track and convict drug dealers and manufacturers. In 'The Acid House'13 an American couple were producing LSD tabs.

Forensic scientists used Gas Chromatography to prove the presence of LSD in pipettes recovered from the property. The forensic scientists matched tabs and designs obtained from raids on the streets to sheets recovered from the property along with computer instructions on design and printing techniques. With this information along with the chemical formulae on a piece of paper which FSS scientists verified as that for the quantities of LSD per tab, the police had enough evidence to convict the American couple.