PC Hollie Matthews of Essex was horrifically attacked whilst on duty two years ago. Today, Declan Diedrick, 25 from Essex has been jailed for five years after stabbing her in the head and assaulting her colleague, Acting Sergeant Gemma Sandy.
Originally charged with two counts of attempted murder, he was found guilty of lesser but still serious offences of causing GBH with intent during what was described in court as a psychotic episode. The judge acknowledged Diedrick was living with mental health problems at the time but qualified this by pointing out his psychotic episode would likely have been exacerbated by his use of illegal drugs.
His mental illness does not explain his offending – he was found perfectly capable of forming the necessary intent to seriously injure.
PC Matthews is obviously an exceptionally brave officer – going towards someone who appears angry and psychotic whilst you know they are holding a seven-inch kitchen knife and whilst unequipped to confront such an offender, takes some doing. Her victim impact statement is partially quoted in the BBC News article covering the sentencing today at Chelmsford Crown Court and it showed obvious signs of how it still affects her to this day.
HELP SEEKING
Coinciding with the recent publication of the Health and Social Care Committee’s report on community mental health services, this judgment serves to remind us of the difficulty faced by people and their families in securing timely, relevant support for unscheduled mental health care. We learned in the sentencing that help for Mr Diedrick was sought at various points between October 2023 and the attack in late December.
No help was forthcoming and the police were called to a disturbance on 29th where PC Matthews was stabbed.
It’s a familiar tale, however – individuals or families calling for support as someone’s mental health deteriorates only for a serious untoward incident to unfold. We’ve all seen plenty of examples of suicide after a non-intervention and in this case, with knives being used to stab someone in the head in a terrifying attack, we’re lucky not to be discussing a mental health homicide and I bet that traumatising fact is not lost on the officers. For the purposes of understanding the incident, it’s a shame we don’t know more about what the relevant health agencies or professionals did with the requests for help from Mr Diedrick’s family.
MENTAL HEALTH & CRIME
This incident also serves to show us (again) something rather important in our discussion and understanding about criminal conduct which is affected by someone’s mental health –
It can be made very complicated indeed to prove someone’s specific intent when they are affected by psychosis and / or by use of unlawful drugs and they offend. We do sometimes find psychotic presentations associated with a mistaken belief someone must “lack capacity” and therefore be beyond the grasp of criminal law and this is not always true. I’d go so far as to say it’s not often true and where the offence is serious, as this obviously is, it will almost always be in the public interest to prosecute. The criminal courts have powers under the Mental Health Act 1983 enjoyed by no police officer, prosecutor or psychiatrist and they can be powers which are necessary at the pre-trial or sentencing stage, to ensure psychiatric reports or medical opinions which can assist the judge in handling the trial and its outcome.
Those powers are not always relevant to mental health related prosecutions, but with serious cases, it’s important they are placed in court wherever possible, so the decision about how to finalise the case is taken by a jury or judge in possession of the fullest information, as police and prosecutors rarely are. We’ve ended up here with no mention of the Mental Health Act at all, the passage of time has no doubt allowed for treatment and we know the defendant wrote a letter of apology to PC Matthews, for what that’s worth. But it still remains an horrific attack on a Crown Servant who fully deserves to see justice done in court – in this case, that involves five years in prison and an extended time on licence after release.
I can only wish both Hollie and Gemma the very best and thank them. The judge said it best, though after commending them for their bravery –
“We depend on people like them. They go into situations like this at risk to themselves” … “I hope in due course they’ll be able to put this incident behind them.”
Merry Christmas to them both.
Awarded the President’s Medal, by
the Royal College of Psychiatrists.
Winner of the Mind Digital Media Award
All opinions expressed are my own – they do not represent the views of any organisation.
(c) Michael Brown, 2025
I am not a police officer.
I try to keep this blog up to date, but inevitably over time, amendments to the law as well as court rulings and other findings from inquests and complaints processes mean it is difficult to ensure all the articles and pages remain current. Please ensure you check all legal issues in particular and take appropriate professional advice where necessary.
Government legislation website – www.legislation.gov.uk
Mental Health Cop 