A large, heavy door swings shut. A sign labelled ‘Scene of Crime Unit’ hangs above the pristine room, which is lined with black and white photographs depicting figures clad in white overalls carefully performing swabs or poring over evidence.

“Forget the glamour and high heels of CSI,” Sergeant Arthur Debattista grins, referring to American television series Crime Scene Investigation.

“We’re normally caked in dirt after a day’s work.”

The forensics department within the Malta Police Force comprises 40 people. Twenty are scene-of-crime officers who work gruelling 12-hour shifts on a day-night-rest-day-off rotation.

“In particular cases, the officers would work beyond their 12-hour shifts – it’s not the first time they’ve clocked in 24 hours,” head of forensics, Inspector Ramon Cassar, explains.

“The same team of crime scene officers work on a particular case in order to ensure continuity.”

A scene of crime officer (SOCO) may perform the dual, but not simultaneous, roles of court-appointed expert and police investigator.

In both, the SOCO is bound to preserve the crime scene, recover and compile evidence and report his findings. In the case he is appointed as a court expert, his reports will be solely submitted before the courts. However, as a police expert, his reports will be forwarded to the senior ranked officers investigating the case.

“We’re not always the first to arrive at the scene of the crime. In effect, the first moments are crucial as we try to piece everything together,” Inspector Cassar says. “When we get there, we’re the people with the least information. By the time the case is closed, we’re the ones with the most.”

Rigour, accountability and integrity of procedure are key. A SOCO’s first action upon arriving would be to photograph the site to document and preserve the crime scene and evidence.

Every photograph and all evidence is logged into a secured digital system and stored on two separate servers to ensure extra security and back-up.

The forensics department has its own printing operator, tasked with printing all photographs to be used at court or for police investigations.

The digital system will automatically generate a random serial code, which is hidden for security reasons.

The department takes the processing and storage of photographs very seriously as they are of vital importance should officers be challenged by the defence in court.

Collecting evidence

The evidence range is huge. Trained SOCOs, many of whom have 10 to 20 years of experience, would immediately know where and what to look out for.

Yet, sometimes, unexpected pieces of evidence such as a stray fingerprint may inadvertently be stumbled upon following a thorough search, as officers from the chemical enhancement unit later point out.

The first piece of evidence we touch upon is gunshot residue (GSR). Close to the barrel, it deposits more heavily on surfaces such as skin and clothing.

Detection of a significant amount of residue, therefore, is a powerful piece of forensic evidence that the particular person was very near to, or even holding, the gun when it discharged.

As an extra precaution, officers who were on the scene of the crime (despite being clad head to toe in protective clothing) or those who undertook shooting range practice less than 48 hours before are not allowed to perform GSR testing.

GSR swabs are taken from a person’s face, hands, neck, hair, nostrils, ears and clothes in the presence of the inquiry magistrate.

The taking of samples from body cavities (except for those taken from the mouth) qualifies as intimate before the law, and thus requires not only the person’s consent but the authorisation of the magistrate.

Shoe marks are classified into two types. Above-the-surface shoe marks, detected on surfaces such as tiles, are preserved using a static lifter which uses an electric current to ‘lift’ the dust/debris.

Below-the-surface marks, which are essentially embedded in soft surfaces such as soil, are preserved in a cast.

Blood is a powerful piece of evidence, Inspector Cassar stresses. Apart from containing important information such as the blood group and DNA, it can indicate the origin of blood stains, the position of victim and assailant, the number of blows or shots and the type of weapon used. Heavy blood splatters, for instance, indicate that the victim’s main artery had been slashed open.

Everything revolves around the evidence collected within the first few hours of a crime

Other pieces of evidence may include glass fragments (lodged in a person’s clothes), fibres of clothes and the tool marks made to break open a door or safe.

“We always work with two principles in mind: the first is Locard’s exchange principle, which states that every contact leaves a trace; the second is the principle of individuality – even though two objects may look alike, they are not identical,” he added.

Analysing evidence

On our way to other units within the building, we pass by one of the department’s mobile stations. It is fully equipped and in pristine condition, though it had been driven over to a murder scene the night before.

We enter the dactyloscopic data unit, where Sergeant Clive Brimmer is staring intently at his computer screen, carefully comparing two fingerprints.

Fingerprint matching is not merely a computer-automated process. The prints are authenticated manually by matching ‘characteristic points’ (formed by random fingerprint ridges).

A large cabinet full of files neatly stacked against each other contain the data of 22,000 suspects and convicted people.

Inspector Cassar draws my attention to a number of frames on every officer’s desk – each containing a security clearance issued by the Office of the Prime Minister, granting them access to investigate sensitive data.

The results of DNA analysis are also processed within this department. They are inputted as a series of values.

“DNA profiling depends very much on the quality of the stain from where it is lifted,” Police Constable Sergio Pisani explains.

A vaginal swab from a sexual assault victim might yield a ‘mixed profile’ – the analyst would need to, for instance, distinguish the profiles of the man involved in the assault from the profile of the victim’s consensual sexual partner.

The chemical enhancement unit, manned by Sergeant Jeffrey Hughes and PC Patrick Farrugia, is responsible for the development of fingerprints (which are not visible to the naked eye). The laboratory is lined with high-tech equipment.

“We use a variety of chemicals in conjunction with light to bring out the fingerprints,” PC Farrugia explains.

“When our body secretes fatty sweat, it may fluoresce when exposed to ultraviolet rays.”

Forensic experts have to be careful, meticulous but also quick and efficient

A small, dark room contains a piece of equipment known as a Quaser, which the officers jokingly refer to as ‘the beast’. Only two people at a time, wearing viewing goggles and full face masks, are allowed to use it. The door of the room is equipped with sensors which cut off the power supply as soon as another person enters.

“If you feel queasy or dizzy, let me know immediately,” Sergeant Hughes warns.

After putting on the protective equipment, he switches off the lights and turns on the machine, which emits filtered wavebands for the detection of latent fingerprints, fibres, body fluids and other trace evidence on objects.

“We sometimes carry this 10-kilo box with us to the scene of the crime. Once, we shone the beam on to a doorframe and a clear fingerprint was made visible. It turned out to be a crucial piece of evidence.”

The print is photographed and transferred on to a digital capturing system, where the officers enhance it.

“I normally convert it to black and white, as black ridges on a white background are best for the people at the dactyloscopic unit. The special software retains an audit trail of any enhancement made to the image in case we’re challenged in court,” PC Farrugia says.

Inspector Cassar sums it up: “Forensic experts have to be careful, meticulous but also quick and efficient. Everything revolves around the evidence collected within the first few hours of a crime.

“At the end of the day, we’re there to serve the court and aid in police investigations. Transparency and rigour are key.”