Karl Walsh, 45, of Eaton Green Road, was found guilty of causing grievous bodily harm (GBH) with intent, assault occasioning actual bodily harm (ABH), and two counts of theft.
At around 9.30am on 21 June, Walsh entered a convenience store in Kimpton Road, and asked for a bottle of vodka, which he grabbed and attempted to run away without paying.
When a staff member stopped him at the store door, Walsh punched him twice, and then hit struck him over the head with the bottle.
This caused severe injuries to the victim, but thanks to help from another staff member, and a member of the public who was passing by, Walsh was detained until police arrived.
Following his arrest, police investigators also linked him to another theft from a shop through CCTV footage.
At 10.10am on 4 June, Walsh was seen entering a building materials store in Gypsy Lane, Luton, on an electric scooter.
There he filled a rucksack with gardening materials, and took a strimmer, which he laid across the scooter handlebars, and attempted to leave through a fire exit, triggering an alarm.
A member of the public managed to stop him, and a staff member took the stolen items back. Walsh then swung the scooter at the member of the public, hitting him in a chin, and made off from the location.
Walsh was sentenced to nine years imprisonment for causing grievous bodily harm with intent for the assault with the bottle, and 12 months for assault causing actual bodily harm at the building materials store, to run concurrently. He was also sentenced to six months imprisonment for each count of theft, to run concurrently.
Detective Constable Michael Wallis, from the Crime Investigation Team, said: “Walsh is a violent and unpredictable individual who was willing to severely injure an innocent person to avoid paying for a bottle of vodka.
“He acted with no consideration for anyone’s wellbeing but his own, and lashed out aggressively when confronted for his criminal actions.
“We are satisfied with the lengthy sentence, which reflects the severity of his actions. He belongs in prison, where he will now spend a long time reflecting on his behaviour.
“I would also like to recognise the bravery of the members of the public and store staff who confronted and detained him. Their public-spirited actions led to his arrest and allowed us to bring this individual to justice.”