According to Thames Valley Police, officers responded to a security breach at around 8.30am within the grounds of Windsor Castle on Christmas Day. The authorities quickly arrested an armed man who was later identified as a 19-year-old from Southampton.
Officers took him to Maidenhead police station, where he was still facing questions on Saturday night.
As seen on CCTV, the trespasser was carrying a crossbow, reports The Sunday Mirror.
One source said: “Security controllers monitoring the CCTV couldn’t believe their eyes when they spotted the man carrying what appeared to be a crossbow and scrambled armed police to the scene immediately as a top-level emergency.
“A full-scale protection plan was executed to ensure the safety of the Queen, who was in her personal quarters.
“It was a really professional response from everyone, but it was hugely alarming to witness the intruder on the scene.
“There were real concerns the situation could have massively escalated having such a dangerous weapon to deal with.
“When word got out that he had been apprehended, everyone breathed a huge sigh of relief – but it’s obviously tremendously concerning.”
Her Majesty was awaiting a visit from her sons Prince Charles and Prince Edward to attend St George’s Chapel service when her security staff raised a “top-level emergency.”
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“I would predict a major review will be needed after this latest incident, which is incredibly worrying, especially as this individual was armed. We don’t know their background or motive, but clearly, this is a major security issue.”
A royal source said: “It is obviously a worry to have to deal with a break-in like this, especially after Her Majesty has been through so much this year and in the lead-up to Christmas.
“There will have to be a major evaluation of the security procedures and protocols after this event.
“Fortunately, the intruder was apprehended, and police were on the scene almost immediately, but there is a chill in the air over what could have been.”