The first pictures have emerged of Jaswant Singh Chail, the 19-year-old youth who has been sectioned under the Mental Health Act after breaking into Windsor Castle armed with a crossbow.

The fact that Jaswant is being held under the Mental Health Act would suggest police are not treating him — to begin with, anyway — as a suspected terrorist.

The NHS has a note on the Mental Health Act that says: “In most cases when people are treated in hospital or another mental health facility, they have agreed or volunteered to be there. You may be referred to as a voluntary patient. But there are cases when a person can be detained, also known as sectioned, under the Mental Health Act (1983) and treated without their agreement….

“People detained under the Mental Health Act need urgent treatment for a mental health disorder and are at risk of harm to themselves or others.”

While he is held in hospital, police are trying to find out why he put on a mask, carried a weapon and posted a video in which he threatened to “assassinate” the Queen as “revenge” for the 1919 Jallianwala Bagh massacre.