The jury heard that many prisoners, including Bevan, were considered vulnerable at the jail due to risk posed by other inmates.
There was “tension” between vulnerable prisoners, or “VPs”, who made up about three quarters of the population, and other inmates, Pitter said.
There was also “bullying” of VPs, who tended to be those who had committed offences of “particular moral repugnancy”, such as sex attacks or crimes against children.
But Pitter said Bevan “kept himself to himself” and was not known to be associated with the defendants in any way.
In 2023, he had been sentenced to life in prison with a minimum term of 28 years for the murder of Lola James, two, in Haverfordwest.
She had suffered “catastrophic” brain injuries following a “brutal” assault from Bevan in her family home in July 2020.
The judge in his trial, Mr Justice Martin Griffiths, described his actions as “an assertion of superiority over the only person he could feel superior to – a helpless child”.
Bevan’s death came less than a month after paedophile singer Ian Watkins, 48, was fatally stabbed in the neck at the same prison.