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Forensic Vacuum Metal Deposition (VMD) – Frequently Asked Questions

Over the past 5 years, forensic VMD has been completely transformed due to West Technology Forensics’ development of the systems and the technique. There are many misconceptions and myths around VMD so to hopefully help dispel a few of them, here are our top 20 questions we’re regularly asked; if you have any of your own, please feel free to add a comment below.

1. What is Forensic Vacuum Metal Deposition (VMD)?

The coating of an item with atomic layers of metal in a vacuum chamber.

2. What types of evidence can be processed with VMD?

A huge range of non/semi-porous and porous items e.g. flexible plastic packaging, paper, plastic bottles, cell phones, glass, fabrics, firearms, fired ammunition, knives, thermal paper, wood, currency, IEDs, latex gloves etc. The UK Home Office recommend forensic VMD for the following:

  • Items exposed to high temperatures (the only process recommended for temperatures as high as 900°C or 1652°F)
  • Items where fingermark residue may have been removed
  • Aged prints (proven to develop prints 20+ years old)
  • Items that have been previously wetted or submerged
3. Is VMD a new fingerprint development process?

No. VMD was first developed by the UK Home Office, Police Scientific Development Branch in the 1970s. However, the old systems were industrial, high maintenance and extremely expensive, resulting in only a few labs worldwide being able to utilise the powerful process.

4. Is the process proven on actual casework?

Yes. The VMD process has been used operationally by Law Enforcement worldwide for 30+ years and is classed as a Category “A” fingerprint development technique by the UK Home Office – Centre for Applied Science and Technology. This is the highest recommendation awarded!

5. Are Forensic VMD systems expensive?

Thanks to the recent development of the world’s first benchtop system (VMD360), the costs are less than 1/4 of the price of older VMD systems. Did you know…You can now actually buy a forensic VMD system for less than the cost of some forensic lasers, 360 scene cameras and fingerprint imaging systems!

6. Is the process expensive?

With the emergence of single evaporation metals, a single VMD process can cost less than a $1. This becomes even more cost-effective when processing batches of items, e.g. 20+ fired cartridges, costing merely cents per item.

7. What are the ongoing consumables for the system?

There are no expensive filters to worry about, just the evaporation metals, the source boats (which hold the metal) and occasionally some new oil for the vacuum pump (usually every 12 months).

8. How much metal is used?

Very small amounts e.g. approx. 4 mg of silver wire (0.25mm diameter).

9. How long does a process take?

Typically 5-10 minutes (exhibit and system dependant).

10. Can you process multiple items in a single VMD process?

Yes, however, we recommend only processing multiple items when they are known to be of the same material type and in the same condition.

11. Is the VMD process safe?

Yes. Proven to be an extremely safe process and doesn’t require expensive filtration.

12. Does VMD affect DNA?

Independent research has concluded that VMD has low interference on subsequent DNA testing, actually making it a good technique to identify areas of touch for DNA sample collection.

13. Does VMD affect ballistic testing?

No, the VMD process is non-destructive.

14. Do you need to be a vacuum expert?

Not at all. The new systems are semi-automated and have been designed by Forensic Scientists to be very simple to use. Most users are competent within a few hours of training.

15. What system maintenance is required?

All our VMD systems have been designed to be extremely low maintenance and recommended to be serviced every 1-2 years, if required.

16. What level of ridge detail can be developed?

3rd level – ridge shape/pore configuration.

17. How does VMD affect the exhibit?

The structure of the exhibit does not change. The amount of metal evaporated will impact the visual look of the item.

18. What size items can be processed?

The VMD1260 is capable of processing larger items such as rifles, whole trash bags and items of clothing.

19. Does the system come with a warranty?

12 months as standard. Extended warranties are available.

20. Which operating languages are available?

The systems operate mostly using icons, however, any text can be translated into different languages, if required.

Thank you for taking the time to read our top 20 FAQs and please, feel free to share the article!