Police first became aware of Michael Pym-Nixson, 54 after paramedics were called to his home to treat him for burn injuries. Because of the suspicious circumstances, police launched an investigation.
Following his arrest, officers found that Pym-Nixson hoarded kilos of substances that, when mixed, are known to create explosive materials.
The investigation was led by the Met’s Counter Terrorism Command, following an initial review of the circumstances using the unit’s specialist expertise. No terrorism connection was subsequently found.
Commander Richard Smith, who leads the Counter Terrorism Command, said: “Pym-Nixson’s pre-occupation with making explosive materials in preparation for a future breakdown of society put himself and others who lived around him at risk.
“He was experimenting with highly dangerous chemicals in uncontrolled conditions, and his actions could easily have resulted in a serious fire or explosion.
“We would urge anyone with concerns about anyone in their neighbourhood who they believe is committing crime to call police straight away – we will act.”
There was no evidence which indicated that Pym-Nixson was creating explosive material for any malign purpose, or had any intention to make an improvised explosive device (IED).
On the evening of Friday, 19 March, paramedics were called to Pym-Nixson’s address on St George’s Road in Kingston-Upon-Thames, to treat burns to his left hand which he said were caused by a firework accidentally igniting.
The following day, officers visited the flat to check on Pym-Nixson’s welfare – he spoke to the officers, but did not let them into his house. On the morning of Sunday, 21 March, officers returned to the flat to conduct a search of the property and arrest Pym-Nixson.
Specialist officers from the Met’s Explosive Ordnance Disposal (EOD) unit remained at the scene throughout the week-long search, and they found large quantities of chemicals used to make explosive material in his house and shed.
On the day Pym-Nixson injured himself, he caused three small explosions by mixing these substances – after making local enquiries, people in neighbouring properties subsequently told police they had heard loud bangs. These weren’t reported to police.
Officers also discovered hand-written notes detailing the quantities of the substances needed to make explosives, and how-to videos online that Pym-Nixson had saved. The notes were said to have been written in 2015 and 2016.
Pym-Nixson was charged on Monday, 29 March. He first appeared at Westminster Magistrates’ Court the following day.
He initially pleaded not guilty to three counts of possessing explosive substances (contrary to section 4 of the Explosive Substances Act 1883).
However, on the third day of his trial at Southwark Crown Court on Wednesday, 3 November he admitted to two of the charges. The third charge will lie on file. He will be sentenced at the same court on Friday, 10 December.