The UK's Crown Prosecution Service spent £30,000 (US $50,000) in a failed attempt to prosecute a speeding ticket issued to school teacher David Jennings, 33, in November 2003. After fifteen court hearings over two years, the government failed to prove that he was driving 60 MPH in a 30 zone on the A379 in Teignmouth, Devon.

Jennings had just received his driver's license and was extremely cautious. In August 2004, a court convicted him in his absence, imposed six penalty points and confiscated his brand new license. Jennings hired a lawyer who was able to secure a new trial and called Dr Michael Clark, the leading expert on laser speed measurement technology, to testify in the case. Clark demonstrated the accuracy problems of the Ultralyte LTI 20-20 speed gun and showed how the device, which was hooked up to a video camera, was operated carelessly. The Totnes Magistrates Court dismissed the case on December 22, 2005.

"I believe my case is the tip of the iceberg and there are many thousands who have received tickets and did nothing wrong," Jennings told the Daily Mail newspaper.

Independent investigations by the Daily Mail and BBC News show the LTI 20-20 that was used against Jennings is susceptible to producing wild errors. The device is the most common mobile speed camera used in the UK and one of the most popular laser speed guns in the US.