Leoaai Elghareeb, 37, sparked panic in the aisles and caused almost £500,000 of damage when he took a bucket full of syringes into stores along Fulham Palace Road.
Isleworth crown court heard the qualified lawyer, who was the director of Opus Legal Contractors, injected blood into apples, ready meals, and a packet of chicken tikka fillets, forcing staff to shutdown the stores as a safety precaution.
Customers and staff were pelted with syringes and eggs by Elghareeb, who also assaulted a security guard during the rampage on August 25 last year.
Jurors heard Elghareeb believed he was under the control of spies and living in a version of The Truman Show, having suffered mental health problems over the previous 12 years.
A first jury could not reach a verdict, but after a retrial Elghareeb was found not guilty on Thursday by reason of insanity.
Prosecutor Philip Stott told the first trial: “In the early evening of a late summer’s day last year, Mr Elghareeb walked down the Fulham Palace Road in west London carrying a bucket filled with syringes, some of which had needles attached.
“A number of those syringe were filled with blood – his own.
“Mr Elghareeb then entered, in turn, three supermarkets on the Fulham Palace Road, in order: Waitrose, Sainsbury’s and Tesco – and proceeded to stick those syringes in food products inside the supermarkets.
“Along the way her threw some of the syringes at people inside and outside the store including hitting a passerby on the street.
“As he was confronted, because of his action, by a succession of store personnel in the supermarkets he assaulted one of them by pushing him, in addition to throwing verbal insults at those around him.”
He told jurors the syringes were found on the floor of the Little Waitrose, while some had been left sticking out of the food packets.
“Once staff realised what had happened, they told everyone inside to drop their shop and leave, and then closed the store”, he said.
“At Sainsbury’s, (Elghareeb) was confronted by members of staff. The defendant pushed one of the security guards on his chest. That was Bilal Ansari. He will tell you that the defendant was shouting things like ‘you are all vile people and Sainsbury’s is vile’.
“He was also swearing at the staff and at customers and throwing eggs, before then leaving.”
Elghareeb was caught on CCTV cameras as he carried out the acts, and also “threw a plant pot through the door of the Avanit restaurant on Fulham Palace Road, narrowly missing a waiter”, said Mr Stott.
A total of 21 syringes were recovered, and the bill ran to £467,000 after the supermarkets carried out deep cleans and threw away contaminated food.
Dr Bradley Hillier, a consultant psychiatrist, gave evidence that Elghareeb was suffering from psychosis when he went on his supermarket rampage.
“There have been multiple times when he has reported the belief that his mind was being interfered with and that a device has been implanted into his ear or brain”, he said in evidence.
“He has reported hearing voices which are talking to him, saying unpleasant things about him.”
Dr Hillier said at the time of the incident Elghareeb “believed he was being monitored by the British secret services, that his telephone had been hacked, and he was trying to seek help from the police.
“But he believed the police and everyone around him was fake. In his mind, he described it as like The Truman Show, a fake world created by people controlling his behaviour.”
Dr Hillier said Elghareeb went to the supermarkets in a bid to provoke the “real” police into arresting him, believing the “experiences he was having would be investigated by way of brain scans to identify the devices in his brain”.
Elghareeb, from Fulham, pleaded not guilty to three charges of contaminating food and two charges of assault by beating. He was cleared by the jury after the prosecution did not dispute the insanity diagnosis.