An unemployed father of two from Peterborough has been told he will serve at least 34 years in prison after being found guilty of the murder of a rare books dealer in Oxford.

Michael Danaher, 50, attacked and killed Adrian Greenwood, 42, in the hallway of his victim’s home on 6 April, after hatching a plan to rob him of a rare first edition of The Wind in the Willows that Greenwood had listed on eBay for £50,000.

A jury at Oxford crown court heard that Danaher had also drawn up a “hit list” of celebrities and wealthy business people he planned to rob and kidnap, and had researched the home addresses of others including Simon Cowell, Gary Lineker and Kate Moss.

Sentencing Danaher to life imprisonment, Judge Ian Pringle QC said the “savage stabbing” had involved “significant planning and premeditation”.

He added: “Despite the fact that at 50 you had no previous convictions, warnings or cautions of any sort, it’s clear that during the course of 2015 you drew up this list – probably to rob or burgle people – or perhaps kidnap people and hold them to ransom, so as to gain funds for yourself.

“It’s clear from the timeline in this case you became almost obsessive about keeping up on famous celebrities.”

Greenwood suffered 33 stab wounds in the assault, including a deep puncture wound to his back, and multiple blunt force injuries. There were also numerous superficial puncture wounds, which a pathologist told a jury at Oxford crown court were consistent with having been tortured for information.

Adrian Greenwood. Photograph: Thames Valley Police/PA Wire

Danaher admitted killing the antiques dealer, but claimed it was self-defence, telling the court that Greenwood had suddenly attacked him with a knife after he made a bad joke. He said he had visited the dealer to discuss buying other cheap books.

Danaher said he had grabbed the blade of the knife to defend himself in the scuffle, but suffered only superficial scratches. He paused to take a selfie of a nick on his cheek as he left Greenwood dead or dying. The book dealer’s body was discovered by his cleaner the following day.

Over the course of a three-week trial, jurors heard that Danaher targeted the Oxford dealer after he listed the rare copy of the Kenneth Grahame children’s book – particularly valuable because it still had its original dust jacket – on eBay in August 2015.

Danaher, who weighed 25 stone, was estranged from his wife, £13,000 in debt and unemployed after falling out with his boss at an engines company in Peterborough, and scraped a living by buying and selling low-value items on the auction site.

After the killing, police found an Excel spreadsheet on Danaher’s laptop that contained Greenwood’s name alongside those of a number of other wealthy individuals Danaher planned to rob or kidnap for ransom. Against Greenwood’s name, he had written: “Expected take: rare books”; “Reason: tosser”. Next to “Modus”, he wrote “Any!!”

eBay listing created by Michael Danaher for the first edition of The Wind in the Willows he stole from Adrian Greenwood. Photograph: Thames Valley Police/PA Wire

Also included on the list, which Danaher called Enterprises, were the model Kate Moss and the Conservative peer Jeffrey Archer, along with a number of wealthy business figures, among them prominent Conservative party donors. Under “reason”, several were marked “Tory” or “scum Tory”.

Danaher also searched for the home addresses of celebrities including Eamonn Holmes, Louise Redknapp and Michael Parkinson and other “people of means”. A floorplan of the home of the TV presenter Anthea Turner was also found on his laptop.

Danaher’s internet history showed he had looked up how to buy samurai swords, regulations on owning rifles, “opening locks without keys” and “the technique of silent killing”.

In a bizarre defence, he attempted to claim it was not him but another man – whom he would not name for fear of “consequences” – that had carried out the searches and drawn up the list. This man would come and go from his Peterborough flat at all hours of the day and night, Danaher claimed, and had full use of his mobile phone and laptop.

Occasionally, Danaher said, he would lend the man his phone and car, which he claimed explained why both had been traced to the home of the wealthy businessman Adrian Beecroft, when a man had tried to force his way in while disguised as a delivery driver. He fled when Beecroft’s wife screamed for help.

After the killing, Danaher took the copy of The Wind in the Willows back to his flat in Peterborough and showed it to his son, before listing it for sale on eBay just hours after the killing.

He was arrested after phone records and numberplate scanning traced Greenwood’s mobile and Danaher’s Citroën Picasso car to Peterborough. The broken murder weapon and a pair of bloodied boots were found at his flat, along with a stun gun, disguised as an iPhone.

