An "infantile" 61-year-old prankster caused £260,000 worth of damage by firing ball bearings at windows with a catapult on his way to work.
Terry Jones, of Lynwood Gardens, Waddon, regularly took pot shots at an office block as he drove to his job as a refrigeration engineer in the early hours of the morning in a "bizarre and inexplicable" vandalism spree spanning six months.
He told Southwark Crown Court he had no connection to the building in Paddington or grudge against its owners, adding: "I fired at it because it was there."
Jones would fire ball bearings out of the window of his van and never actually stopped to see if he hit his target, 3 Sheldon Square, the court heard.
He smashed 13 panes between October 2014 and March 2015 before police tracked him down via his number plate.
Each pane of glass cost the building's owner Paddington Central Management £20,000 to replace.
Jones admitted 13 counts of criminal damage at magistrates court, but insisted he had not even heard the windows break.
He did not know anyone in the building which lists companies like Kingfisher and Prudential amongst its tenants and he had never worked for the company that owned the building.
Handing Jones a 12-month jail sentence suspended for a year on Wednesday, Judge Andrew Goymer said: "This is about as bizarre and inexplicable a case as I've ever had to listen to.
"What I have been told is that you, a man now 61 years of age, just turned 60 at the time of these offences, took it upon yourself on about a dozen occasions to use a catapult to fire projectiles at a building.
"You didn't know anyone in the building, you didn't have a grudge against them or anyone who employed them, you just happened to be going past in your van on your way to work.
"To describe this behaviour as infantile is probably as much of an understatement as one can make – this is the sort of behaviour that if it was done by a 10-year-old you would say they should be beyond it."
He continued: "Your sense of humour prompted this warped practical joke but there's a very serious aspect to it. Firstly, there was a huge amount of damage.
"If you break windows in a building like that, the replacement glass has to be of a very high quality and must be of a certain safety specification – behaviour like this doesn't come cheap.
"Secondly it's serious because the people working in the building could have been hurt, you are not charged with criminal damage being reckless as to whether life was endangered and it's just as well you are not because you would have had a considerable custodial sentence.
"The gap between you going to prison and staying out is so narrow you can't see daylight through it."
Jones, who has no previous convictions, was also ordered to pay £2,000 compensation and complete 240 hours of unpaid work.
Judge Goymer added that there was not a single case to help him determine sentence, and the closest he had found was examples of teenage graffiti artists damaging trains.
Mark Sahu, Jones's lawyer, said his client had driven the same route to work every day for the last 30 years.
"The only reason he chose that building was because it was in his line of sight," he added.
"He comes to this court with a great sense of shame. One wouldn't expect a man of his age to be before the courts, and that's what makes it even more unusual."
Mr Sahu added that there were no mental health issues that could explain Jones's behaviour.
Jones thanked the judge as he left the dock.