Two prisoners who kept watch while another inmate stabbed Kettering baby killer Andrew Randall had their sentences lengthened when they appeared at Northampton Crown Court this week.
Robber Patrick Maughan, 38, and convicted murderer Arthur Pitt-Pladdy, 41, had 10 and five years added to their sentences respectively on Tuesday for their parts in the attack, in which another prisoner stabbed Randall in both eyes and slashed his throat using improvised weapons.
The assault took place on August 13, 2011, at Long Lartin Prison in Worcestershire.
The court heard that Maughan and Pitt-Pladdy kept watch for prison officers and also cancelled alarms which were raised, meaning the attack was not discovered for some time.
The man who carried out the attack, murderer Jason Jay, is due to be sentenced at Worcester Crown Court within the next two weeks after pleading guilty to attempted murder.
Maughan had admitted a charge of encouraging or assisting the commission of an offence while Pitt-Pladdy pleaded not guilty.
However, the jury at Northampton Crown Court found him guilty this week. When the verdict was announced Pitt-Pladdy swore at the jurors and said they had made a mistake.
The court was told that Maughan had an extensive criminal record. While serving a five-year sentence for robbery he attacked another inmate and was given a further prison term of four-and-a-half years.
Pitt-Pladdy was jailed for a minimum of 17 years in 2009 after murdering his girlfriend in Saundersfoot, Wales, when he stabbed her 177 times.
In court on Tuesday, Judge Rupert Mayo said the additional sentences given to Maughan and Pitt-Pladdy reflected their respective roles in the attack.
He said Maughan had been involved in the planning, while Pitt-Pladdy had only become involved moments before the incident.