An inquiry has been launched by a mental health trust after one of its paranoid schizophrenic patients bludgeoned a stranger with an axe in Finsbury Park, leaving him brain-damaged and permanently disabled.

As reported in last week’s Gazette, Thomas O’Connell, 26, of Green Lanes, Finsbury Park, was detained indefinitely in hospital on Friday after admitting the attempted murder of Marcin Dzioba on December 28 last year.

He had bought the axe from Homebase and approached Mr Dzioba from behind as he sat on a bench in the park at about 11pm, injuring him so severely his brain was exposed through his cracked skull. It was initially thought he would die, and while Mr Dzioba made a remarkable recovery, he requires 24-hour care.

Almost a year later the Camden and Islington NHS Foundation Trust (CANDI) is still investigating why its staff secured a flat for O’Connell in the community just weeks before the attack, rather than detain him in hospital.

He had not been taking his medication regularly for up to six months before the attack, and was on police bail for threatening to kill his mother.

Sentencing O’Connell, Judge Timothy Pontius said it was a “matter of great concern” that he had not been detained in a secure hospital.

Wendy Wallace, CANDI’s chief executive, said: “We are conducting a full and frank inquiry into Mr O’Connell’s care, which has not yet been concluded. We were profoundly shocked by the attack on Mr Dzioba, and wish to express our sympathy to him and his family.”