The father of a man arrested in the grounds of Windsor Castle allegedly in possession of a crossbow has reportedly said “something’s gone horribly wrong with our son”. The Metropolitan police are investigating a video, which has been linked to the 19-year-old suspect, who was arrested on suspicion of breach or trespass of a protected site and possession of an offensive weapon and was subsequently sectioned under the Mental Health Act. The video, obtained by the Sun, appears to show a masked figure in a dark hoodie holding a crossbow and addressing the camera with a distorted voice, saying they want to “assassinate the Queen” in a “revenge” mission for the 1919 Jallianwala Bagh massacre, also known as the Amritsar massacre. MailOnline reported that the man’s father said: “Something’s gone horribly wrong with our son and we are trying to figure out what. “We’ve not had a chance to speak to him but are trying to get him the help he needs. From our perspective, we are going through a difficult time. We are trying to resolve this issue and it’s not easy.” The Queen spent Christmas Day at Windsor Castle and was expected to have lunch with the Prince of Wales and the Duchess of Cornwall, and the Earl and Countess of Wessex. Charles, Camilla, Edward and Sophie, the latter couple along with their children Lady Louise and James, Viscount Severn, attended a church service in St George’s Chapel, in the castle grounds, at 10.45 on Christmas morning. A spokesperson from Scotland Yard said: “Security processes were triggered within moments of the man entering the grounds and he did not enter any buildings. Following a search of the man, a crossbow was recovered.” They added: “Inquiries into the full circumstances of this incident are being progressed by Metropolitan police specialist operations.” In the video obtained by the Sun, the voiceover says: “I’m sorry. I’m sorry for what I’ve done and what I will do. I will attempt to assassinate Elizabeth, queen of the royal family. This is revenge for those who have died in the 1919 Jallianwala Bagh massacre.” In the Jallianwala Bagh massacre, 379 protesters were killed and 1,200 wounded by British forces in India. The Met would not comment on who appeared in the video but a spokesperson said: “Following the man’s arrest, detectives are assessing the contents of a video.” In 2003, Aaron Barschak, a former comedian, gatecrashed Prince William’s 21st birthday party in an incident that led to a review and ultimately a tightening of security across royal residences. The review also recommended a new offence of trespass into royal or government premises, under which the 19-year-old was arrested on Saturday.