Friday, July 17, 2020

An improved process for the collection and DNA analysis of fired cartridge cases

Must read

Boston bombing jury sees blood-stained note written by suspect in boat

Jurors in the trial of accused Boston Marathon bomber Dzhokhar Tsarnaev on Tuesday saw photographs of a blood-stained, hand-scrawled note speckled with bullet holes...

3D printing company brings evidence to life in criminal trials

The courtroom is traditionally a place steeped in history, and governed by laws that were passed many centuries ago. But one Florida-based company wants...

DNA matches not possible for remains believed to be missing Mexico students’

Forensic scientists trying to identify remains believed to belong to some of 43 missing students missing in Mexico have failed to find sufficient usable...

New forensic link could bring closure in brutal Canberra cold case murder

Fifteen years on from one of Canberra's most brutal unsolved murders, a new forensic link has brought the killer closer to justice. Police say they...
Michael Whyte
Crime Scene Officer and Fingerprint Expert with over 12 years experience in Crime Scene Investigation and Latent Print Analysis. The opinions or assertions contained on this site are the private views of the author and are not to be construed as those of any professional organisation or policing body.
- Forensic Podcast -

Improvements to the DNA analysis of fired cartridge cases have been made in recent years, yet successful analysis of this important evidence type remains difficult.

A study published recently in Forensic Science International: Genetics, describes both a novel device for the collection and transport of fired cartridge cases and a new DNA recovery method that incorporates a rinse-and-swab technique.

This technique combines two different types of swabs and a rinse solution with additives that reduce the degradative effects that copper has on DNA. Studies suggest that copper may inhibit downstream PCR and/or degrade DNA through oxidative damage. It is hypothesized that DNA damage is the result of oxidative stress from free radicals due to the reduction of transition metals (i.e. copper). 

The researchers developed a new DNA recovery method, along with a series of rinsing and swabbing steps to reduce the deleterious effects of copper contained in brass cartridge cases and to maximize the recovery of DNA.

The new recovery method yielded approximately threefold more DNA than the traditional double swab method and reduced the evidence of degradation. 

The researchers then tested this new method on real case work applications by testing over 100 cartridge cases collected from crime scenes. Approximately 67% of the time (8 of 12), at least one DNA profile suitable for comparison was obtained from fired cartridge cases assumed to be associated with a single firearm using the collection device and the rinse-and-swab method when the fired cartridge cases were collected within 24 hours.

To learn more about this study and the new DNA recovery method;

Read the Paper here

An improved process for the collection and DNA analysis of fired cartridge cases, Forensic Science International: Genetics, https://doi.org/10.1016/j.fsigen.2020.102238

- Advertisement -

More articles

- Advertisement -

Latest article

Using the NCIC Bayesian Network to improve your AFIS searches

This National Crime Information Centre (NCIC) Bayesian network is based on the statistical data of general patterns of fingerprints on the hands...

DNA decontamination of fingerprint brushes

Using fingerprint brushes across multiple crime scenes yields a high risk of DNA cross-contamination. Thankfully an Australian study has discovered a quick and easy way to safely decontaminate fingerprint brushes to prevent this contamination risk and allows the brushes to be safely reused even after multiple cleaning cycles.

Detection of latent fingerprint hidden beneath adhesive tape by optical coherence tomography

Adhesive tape is a common item which can be encountered in criminal cases involving rape, murder, kidnapping and explosives. It is often the case...

Presenting Fingerprint Comparisons in Court using Forensic Comparison Software

This video gives the fingerprint technician some ideas on how to present a Fingerprint Comparison result to the court that looks professional. To accomplish this...

New modified fingerprint chemical that fluoresces touch DNA on clothing

In sexual assault and burglary investigations, the recovery of DNA from items that have been handled by the suspect is very important....