A man has been found guilty of trying to buy a hand grenade allegedly to blow up a police station.
Mohammed Chowdhury, 24, of Tower Hamlets, handed over £300 in exchange for the explosive device on February 5 last year.
Following the verdict on Wednesday, jurors were told the defendant had also admitted four charges of possessing terrorist material.
At the time of the offences, Chowdhury had been in breach of a suspended sentence for waving an axe at a man outside a Tube station.
Having been caught on CCTV, Chowdhury appeared to direct his rage against the police.
The Old Bailey heard the likely target for his grenade attack was Bethnal Green police station in east London.
Chowdhury was stopped because the weapons dealer was in fact an undercover police officer.
While he was in prison awaiting trial, Chowdhury revealed to family members what he intended to do.
In a phone call with his mother, he said: “I don’t care about the judge or the police and that. I wanted to hurt one of them, innit. I was getting annoyed.
“If I would have got that, I would have chucked it at the station, innit, I don’t care.”
Prosecutor Alistair Richardson told jurors: “When he tried to buy that hand grenade, he was intending to use it to endanger lives, or cause serious damage to property.”
On January 31 last year, the undercover officer known as Gary was tasked to make contact with the defendant, known as Buyer.
He sent a message: “I understand u need some merch?”
The defendant replied: “yes. I’m interested in three grenades.”
On being told the cost was £300 each, Chowdhury replied: “I need 3 for £900.”
Later, he inquired about other weapons but Gary told him they would focus on grenades first.
On February 5, they met at a coffee shop in Wanstead, east London, where Chowdhury, seemingly flustered, said he could only get £300 for one grenade.
They arranged to meet at Leyton Tube station to make the trade with another undercover officer.
Asked if he knew how to handle a grenade, Chowdhury said: “Yeah, take it and like 30 seconds and then you chuck it or something like that.”
Asked if he wanted the “real thing”, he replied: “Yeah.”
After armed police swooped to arrest him, Chowdhury asked: “This isn’t a joke, is it?
“Can you be a bit lenient? I’ll pray to God and promise never to do anything like this again.”
In a search of his flat, police recovered a “shopping list” including handcuffs, nitrite gloves, and strong acid.
Underneath “police Cheetah remote stun gun, lock picks and sharp survival knife”, the word bought was written.
An examination of his mobile phone indicated that he had downloaded information on making explosives.
He appeared to have attempted to buy a balaclava, lock picks, a stun gun and a handgun online, jurors heard.
In a note saved on his phone, he had written about wanting his family dead, saying “also I feel I want to commit mass murder and kill myself before the police get a chance to arrest me”.
While awaiting trial, Chowdhury made a number of phone calls to family members, referring to the hand grenade as “the thingy”.
He said: “Yeah I want to chuck it in the station area. That’s why I wanted to get three of them.”
Chowdhury went on to explain he wanted to “do something serious like on the TV”.
On April 2 last year, he said: “That’s why I got that thing because I wanted to chuck it in the station place because I’m getting so (angry), innit.”
The court was told the attempt to buy a hand grenade followed a brush with the law the year before.
On November 19 2019, the defendant was pushed from behind by a man outside Stepney Green Underground Station.
He ran off, only to return armed with a short-handled axe in his hand tied to his body by a length of cord.
Chowdhury brandished the axe, waving it around, at a second man who ran off.
Following the incident caught on CCTV, he pleaded guilty to having a bladed article in a public place.
Mr Richardson said: “It is relevant to these events because it shows the defendant is a man who is prepared to threaten and use weapons he has got hold of.”
Judge Philip Katz QC adjourned sentencing until March 23.
Commander Richard Smith, head of the Met’s Counter Terrorism Command, said: “Chowdhury downloaded a number of extremely concerning documents and manuals, containing details of how to create and deploy explosives and lethal weapons. What’s more, he then made very serious attempts at trying to get hold of a hand grenade.
“These are extremely serious offences and the public are undoubtedly safer following this investigation and outcome.”