‘Nerdy’ science buff claimed he had caused explosion in garden shed, court told

A “nerdy” science buff claimed to have caused an explosion while carrying out experiments in his shed, then blamed a life-threatening allergic reaction on his mother’s potpourri, a court has heard.

Harry Whittaker, 33, is on trial at the Old Bailey charged with making and possessing explosive substances at the semi-detached home he shares with his mother in the Bedfordshire village of Caddington, near Luton.

Opening the case on Tuesday, prosecutor Emily Dummett said: “This case is all about items found at the defendant’s home for the most part in his shed but also in his bedroom when police had reason to search the premises in May 2024.”

Explosive items allegedly included: black powder; pyrotechnic stars; flash powder; fuses; blank and live ammunition; chemicals; lethal poisons; and suspected improvised explosive devices.

Police seized an instruction manual all about how to make explosives, known as “Uncle Fester”.

They also uncovered radioactive materials and white phosphorus, a substance which can spontaneously ignite in air and is so dangerous that it had to be destroyed by controlled explosion by the military, the court was told.

Ms Dummett said the prosecution case was that a shed window was damaged by an explosion caused by one the defendant’s experiments.

The stash was uncovered after Whittaker called 999 last April 18 to report he was suffered from suspected anaphylaxis, a life-threatening allergic reaction.

When paramedics arrived, they observed he had hives and was wheezing and agreed with the defendant’s diagnosis but had trouble working out what had caused it, the court heard.

Ms Dummett told jurors: “He said he had been conducting experiments with a quantity of chemicals in his laboratory.

“The defendant then showed paramedics inside his shed which he referred to as his laboratory.

“The paramedics observed the shed did not have any ventilation system although one window was broken.

“He said it had occurred during a previous experiment which had resulted in an explosion.”

The medics relayed their concerns to the police, who came to search the address on May 6 2024.

When he was arrested nearby, Whittaker was found to have a wrap of heroin, the court was told.

In police interviews, Whittaker said he used his lab for “experiments” and was trying to collect every element of the periodic table.

He told officers that he “liked to have fun with pyrotechnics” and was “astounded to be arrested for having an educational interest in science”.

He said: “I take precautions so it doesn’t harm anyone. I don’t make things dangerous. It’s all just harmless fun, essentially. I’m just a nerdy kid who likes doing science”.

Asked if he was ever reckless in his experiments he replied: “No, definitely not”.

He said that he marked bottles with a skull and crossbones because it looked cool.

He denied that he had caused an explosion in his shed, saying the paramedics’ report was “horse shit”.

Whittaker told police he did not know what had caused his illness, saying the allergic reaction could have been triggered by anything, even his mother’s potpourri.

The defendant, who has autism spectrum disorder, also told police that he used heroin in the evenings but he did not feel an impairment as a result.

However, Ms Dummett told jurors that Whittaker’s class A  drug use should be viewed with a “cool head” in assessing the risk he posed.

The prosecutor said neighbours would give evidence about what they had seen of the defendant’s experiments and escalating drug use.

One reported seeing “plumes of smoke” coming over the tops of the houses in the neighbourhood, the court was told.

Another neighbour heard a “loud bang” and observed the defendant walking away fast as “thick dark smoke” spewed from his shed, it was alleged.

He had noted that over the past two years, Whittaker had become obsessed with his work shed and spent a large amount of time there.

At times, the defendant seemed “disorientated” and incapable of opening the front door, it was claimed.

Whittaker has denied four counts of possessing an explosive substance and two counts of making an explosive substance on or before May 6 last year.

He has admitted a charge under the Poisons Act and having ammunition without a licence.

The Old Bailey trial continues.