Analysis of homemade 3D printed assault rifles at The University of Warwick has helped convict a criminal in a groundbreaking case.

Several homemade 3D printed guns were seized by West Midlands Police at the home of David Biddell-Portman in December 2020 as part of Operation Captiva, a Police response designed to reduce firearm deaths across greater Birmingham.

Professor Mark Williams, an expert in 3D printing and scanning at Warwick Manufacturing Group (WMG) was called in by West Midlands Police. His 3D scanning machines are 100 times more powerful than a hospital CAT scanner and can view images in detail smaller than a human hair.

By using his cutting-edge technology to scan the weapons, Mark was able to discover the amounts of metal and plastic in each of the weapons. This is achieved by analysing the different densities of the materials.

This crucial evidence helped prove that these homemade guns would be working and potentially deadly weapons. It also showed the levels of sophistication, effort and premeditation that went into the construction of the guns.

This evidence was crucial in securing a conviction, with the defendant receiving a five-year sentence.

Professor Mark Williams said: “It’s satisfying to see justice served, and I’m glad to use our technology in any way we can to help the efforts of West Midlands Police.

“By making this sort of technology available to the public sector, we’re ensuring it’s not just big companies that have access to cutting edge techniques.

“A dangerous criminal is now off the streets thanks to the efforts of West Midlands Police, and I look forward to our continuing work with them.”

By scanning the guns, Police ensured that the judge and jury were aware of the extensive use of metal in the weapons – a sure sign that, when completed, they would have been working and potentially deadly weapons.

It also meant that the state of the guns was recorded if they deteriorated during test firing of the weapons by Police, something that often occurs with 3D printed guns.

The scanning also ensured that the Police, judge and jury could understand the evidence surrounding the weapons.

For many, 3D printed weapons have never been encountered before, and are often irregular and defy categorisation due to their black market, homemade construction. With the scans, Police could identify the closest professionally made weapons and make comparisons.

Michelle Painter, Deputy Head of Forensics at West Midlands Police commented: “This partnership is invaluable to West Midlands Police, the strength and commitment is truly unique and the boundaries are limitless.

“The application of the use of Micro CT scanning in criminal cases continues to be innovative and ground-breaking and progresses investigations and brings justice for victims.”

The conviction is the latest success in the decade long partnership between Professor Williams, WMG, Warwick and West Midlands Police. They recently marked a milestone, with the scanning technology having been used in over 300 cases since 2014.

The full paper on the case can be read here.