The case of Kevan Thakrar, a triple murderer locked up in Frankland Prison in Durham, poses serious questions for the criminal justice system.

Thakrar admitted stabbing three prison officers with a broken bottle and was yesterday cleared of attempted murder and wounding with intent.

The reason for his acquittal was that he was suffering from post-traumatic stress disorder caused by his previous prison experiences.

So where does that leave prison officers? At increased risk of attack from inmates who can use the precedent set by Kevan Thakrar, that they were suffering from the stress of being in prison.

I find it quite incredible that someone can admit a violent attack but escape justice for it because they were under "stress" in prison, having been locked up for previous violence.

I can understand the outrage felt by members of the armed services who are suffering from post traumatic stress disorder from the horrors of war.

And I can understand why the Prison Officers' Association is now seeking legal advice about pursuing a private prosecution against Kevan Thakrar.

The law needs testing on such a potentially dangerous ruling.