Guardian U.K. How Lennon was caught:
News: Police report reveals truth behind 1968 drug raid on the Beatle's home.
...Detective Sergeant Norman “Nobby” Pilcher, who built his drug squad career targeting musicians, including Mick Jagger, Brian Jones, Eric Clapton and Donovan, finally turned his attention to the biggest prize of all - a Beatle - in October 1968.
A confidential Scotland Yard file, which was released at the National Archives to the Guardian under the Freedom of Information Act, shows that Pilcher came under strong pressure from the then home secretary, James Callaghan, after the raid on the Marylebone flat.In his report, hand-delivered to the home secretary, Pilcher tried to explain why it had taken seven police officers and two dogs to raid Lennon's flat, and how it was that the press managed to arrive on the scene within minutes of the drug bust.
It was widely believed that Lennon had already immortalised Det Sgt Pilcher as “Semolina pilchard” in the Beatles song I Am the Walrus. The Beatle described him as a “head-hunting” cop: “He went round and bust every pop star he could get his hands on, and he got famous. Some of the pop stars had dope in their house and some of them didn't.”
On this occasion Lennon was confident that he didn't. At the time he lived with Yoko Ono in the flat he rented from George Harrison at 34 Montague Square. The previous tenant had been Jimi Hendrix. Lennon had been tipped off three weeks earlier by Don Shorter, a Daily Mirror journalist, that Pilcher had him next on the list and he had the flat meticulously cleaned in the belief that Hendrix must have left some trace of drugs in the apartment.
Lennon always insisted he had been framed by Pilcher, who was subsequently jailed for corruption because of his practices in the drug squad. Lennon was fined £150 for possession but the conviction was to give him years of trouble and pain. It was enough to trigger a deportation order against him in the US in 1971, and a subsequent four-year battle against being thrown out. Ono said it also contributed to the couple losing custody of her daughter, Kyoko.
Sounds like Lennon got set up. I suppose the 'drug war' has been phony from its inception, still amazes me that the never-ending war against personal liberties continues.