Harlow: Man convicted of seriously injuring police officer

“They are an example of the incredible bravery of all our officers trying to do the best for the people they serve, putting others first and putting themselves in harm’s way.”

Officers who faced arresting a man trying to assault them with a knife have seen him convicted at court.

Declan Diedrick left one officer with an injury to her face which required urgent hospital treatment in an attack in Harlow on 29 December 2023.

We received calls with concerns for the safety of Diedrick, 25, of no fixed abode, in Hull Grove on the evening of the incident, before the first two officers at the scene were made aware he was also in possession of the seven-inch serrated kitchen knife.

When they tried to get him to put it down, an altercation with the officers began and Diedrick stabbed one of them before being handcuffed on the floor.

A member of the public also helped officers restrain Diedrick, who he did not attempt to stab.

Diedrick previously admitted wounding without intent and possession of bladed article in a public place, however prosecution proceeded with trial where he denied further charges against him – he was found guilty of causing grievous bodily harm with intent by a jury at Chelmsford Crown Court on 30 October 2025.

Following the conviction Detective Superintendent Dan Morrissey said:

The determination and violence Diedrick showed that night was truly horrifying.
One of the officers attacked described the Diedrick’s actions as like something from a Scream film – that is not something any officer should have to expect when responding to a call for help. He specifically targeted officers, not the members of the public also trying to stop him.
Despite everything the officers attending went through they remain in frontline policing duties to continue helping the people of Harlow.
The officers that responded that night are examples of the incredible bravery of all our officers trying to do the best for the people they serve, putting others first and putting themselves in harm’s way.

In a statement the injured officer gave in court, she described her approach to supporting calls for people who may be in crisis:

During my experience as a police officer I have faced lots of jobs with concerns for someone’s safety.
Each one is different but encompasses the same need for an individual facing a crisis. We respond according to the needs of the individual, often those actively trying to hurt themselves or expressing desires of suicide.
I when responding to this call I did what I do at every mental health call; I wanted to help and offer support and safeguarding to the individual in crisis.

Chief Constable Ben-Julian Harrington said:

"I want to praise the bravery of the officers involved in this incident.

"Police officers run towards danger to keep the public safe and it is the professionalism and commitment to our neighbourhoods and communities shown here that the public can expect from us each and every day.

"Thankfully incidents like this are quite rare but it is an example of the lengths my officers will go to keep you safe and protect the public from those who pose them a danger."

Chair of Essex Police Federation, Steve Martin, said:

Despite the severity of the assault our officers demonstrated exceptional courage and professionalism, successfully restraining the individual and preventing further harm. Their actions reflect the highest standards of policing and public service and I am immensely proud of them.
Having viewed the footage of the incident which shows the terrifying nature of the attack, it is difficult to comprehend the fear and danger the officers faced. Diedrick continued his attack even after a brave member of the public intervened - an act of heroism that prevented an even more tragic outcome, for which I thank him.
These first responding officers are a credit to Essex Police. Their bravery and resilience in the face of such violence deserves recognition. I extend my deepest admiration and support to them as they continue their recovery and return to duty.
This incident serves as a stark reminder of the dangers officers face daily. It is my hope that the judicial system delivers a custodial sentence that reflects the seriousness of this attack and sends a clear message: assaults on police officers will not be tolerated.

Detective Superintendent Dan Morrissey added:

From arriving at the scene to Diedrick’s arrest there was less than 60 seconds. That timeframe really highlights the professionalism of effectiveness of those officers first on scene, and shockingly how quickly he could have injured them further.
This investigation and outcome were only possible thanks to the combined efforts of dozens of officers from across the force, the testimony of our officers and the work of crown prosecutors. I’d like to thank all those who played a role in securing this conviction and we await his sentencing.

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