Robert Maudsley’s first victim was a labourer who picked him up for sex in 1973 and showed him a picture of a child he had abused

A serial killer who marked his 64th birthday in prison this week is now one of the longest-serving inmates to be held in solitary confinement.

Robert Maudsley has spent 43 years in detention — 39 of them in special units designed for the most dangerous and disruptive prisoners.

He has been unable to mix with other inmates for most of that time and is in a close-supervision centre in Wakefield high-security jail where he spends most of his day alone in his small cell. A minimum of four staff unlock the unit and remain at a distance when he collects meals.

Maudsley, who was born in Liverpool, killed four people, including a fellow patient in Broadmoor and two other prisoners. The first killing was in