Preston, of Haverhill, Suffolk, sent written threats to different educational and business establishments in 2013.
These included the DVLA headquarters in Swansea, Westfield Shopping Centre in London, Freeport Shopping Centre in Braintree, Transport for London, and a Premier Inn close to Stansted Airport.
In some cases, he suggested that the white powder was deadly – it was later found to be talcum powder.
However, several of the packages he sent contained notes telling the reader to run or hold their breath.
The defendant had no links to any of the establishments, and there was no apparent motive for sending the letters. When Preston was arrested for a separate offence in July 2020, police established him as the main suspect.
His DNA and fingerprints matched that found on the packages and he was arrested in September 2020. Handwriting analysis confirmed that he had written some of the notes.
Preston was charged with 21 offences of sending a hoax substance or other thing, and pleaded guilty to all charges in August 2023.
Following a cold case review, Preston’s DNA from a jacket was then also linked to an indecent assault at knifepoint against a woman in Rainham, Essex, in 1988.
He pleaded guilty to indecent assault and possessing a knife during the 1988 incident in November 2023.
Preston was jailed at Woolwich Crown Court today to a total of nine years and six months, and placed on the Sex Offenders’ Register for life.
The prosecution followed an investigation by the Eastern Region Special Operations Unit (ERSOU).
Nick Price, Head of the CPS Special Crime and Counter Terrorism Division, said:
“The actions of Gary Preston caused severe disruption, concern and fear at a wide range of public establishments given the suspicious nature of his actions.
“Following a cold case review, his DNA was then linked to an indecent assault at knifepoint from 1988.
“I hope this conviction and sentence provides some reassurance that this man has now been brought to justice.”
Hannah Wilkinson, Head of ERSOU’s Counter Terrorism Policing unit, said:
“By targeting places such as primary schools and airports, there’s no doubt that Preston had set out to cause as much distress and worry as he could.
“It is also clear that, by sending these packages to more than 20 organisations across the country, he had spent significant time planning and attempting to cover his tracks.
“ERSOU’s detectives continued to track the investigation and as soon as new evidence became available, our teams were able to step up enquiries once more.
“It’s a positive outcome that Preston will now spend a significant spell behind bars.”
[Lead image: DVLA Swansea]
Rainham is in London not Essex.