What is the significance of forensic light source in criminal investigation?

What is the significance of forensic light source in criminal investigation?

A forensic light source is a crime scene investigator’s and lab technician’s tool for enhancing observation, photography and collection of evidence including latent fingerprints, body fluids, hair and fibers, bruises, bite marks, wound patterns, shoe and foot imprints, gun shot residues, drug traces, questioned …

What is wavelength in forensic photography?

Fluorescence. Alternate Light Sources (ALS) or Forensic Light Sources (FLS) emit a specific wavelength of light, typically between 200 and 700 nm. These wavelengths, used in conjunction with barrier filters, allow substances to be seen that cannot be seen by the naked eye.

What is the importance of light in forensic photography?

It is most important for forensic photographers to understand the physiological changes that take place during a skin injury. These changes from a normal state to an injured state to a healing state permit us to differentiate among the contusions illuminated by light sources of various wavelengths.

How do forensic scientists use light to collect evidence?

The primary application of a Forensic Light Source is for enhancing the detection of latent fingerprints. The use of fluorescent enhancement processes that compliment a light source greatly increases the types of surfaces from which a latent fingerprint can be detected.

What is the purpose of using a forensic alternate light source?

Alternate Light Sources are typically used in crime scene investigation to identify many forms of evidence. Physiological fluids (semen, urine, and saliva) can be identified through their natural fluorescent properties utilizing UV light.

What makes blood an important crime scene evidence which may seem invisible visible?

At present, blood stains are detected using the chemical luminol, which is sprayed around the crime scene and reacts with the iron in any blood present to emit a blue glow that can be seen in the dark. …

Why light is important in capturing an image of an object?

Lighting is a key factor in creating a successful image. Lighting determines not only brightness and darkness, but also tone, mood, and atmosphere. Therefore, it is necessary to control and manipulate light correctly in order to get the best texture, vibrancy of colour, and luminosity on your subjects.

What are light properties?

The primary properties of light are intensity, propagation direction, frequency or wavelength spectrum and polarization. Its speed in a vacuum, 299 792 458 metres a second (m/s), is one of the fundamental constants of nature. The main source of light on Earth is the Sun.

What is light and why it is important in photography?

What is importance of light?

Light is responsible for all life, for the production of the air that we breathe, the cycles of our oceans, the magnetic fields around our planet, gravity, warmth and our weather. We omit the importance of the true nature of the projection of our sun at our peril.

How is fluorescence used in forensics?

Fluorescent microscopy techniques have been widely used within forensic science to assist in the visualization of latent fingerprints, identification of GSR and examination of other types of trace evidence.

What are two forensic uses for light at a crime scene?

Ultraviolet (UV) light technologies are used for multiple purposes in forensic investigations, including authenticating paintings and other fine art, authenticating signatures, analyzing questioned documents , illuminating latent fingerprints at crime scenes and trace evidence on clothing, analyzing ink stains, and …

What is Crime-lite led forensic light source?

This LED forensic light source called Crime-lite uses filters of different colours along with viewing goggles to reveal blood splatters and fingerprint evidence otherwise difficult to detect just by looking.

Why do investigators shine blue lights at crime scenes?

That blue light you always see the CSIs shining on the crime scenes while wearing big orange goggles is not some science version of a psychedelic party. What investigators are doing in that situation is making use of a forensic light source to see hidden objects or objects in a different way than under normal light.

What happens when light is absorbed or re-emitted?

In special situations, the light that is shined on an object is absorbed by that material and then re-emitted at a different wavelength (called a Stoke’s shift), which is known as fluorescence. Typically when an object fluoresces, the light is re-emitted at a lower energy state, and therefore, at a longer wavelength.

When can a broken glass be used as evidence?

It can occur as evidence when it is broken during the commission of a crime. Broken glass fragments ranging in size from large pieces to tiny shards may be transferred to and retained by nearby persons or objects.