An immigration tribunal decided that Laith Alani, a paranoid schizophrenic, should not be deported to Iraq because it would breach his human rights and put people there at risk.
Alani has spent the past 19 years in a secure hospital after he killed two NHS consultants in a frenzied attack because he believed he had received a "command from Allah".
The Home Office wanted to deport him on his release to protect the British public, but he appealed to the Asylum and Immigration Tribunal (AIT) where a panel led by Lance Waumsley, a senior immigration judge, ruled that he could remain in the UK.
The widows of the two doctors, who were not informed of the killer's legal victory or the plans to release him back into society until they were contacted by The Sunday Telegraph, expressed their shock at the decision.
One of the reasons given by the judges is that if Alani was sent back to Iraq he would be unlikely to receive medicine which keeps his paranoid schizophrenic under control.