PC Gell admitted his “lapse of judgement” amounted to gross misconduct following an investigation by Nottinghamshire Police’s Professional Standards Directorate (PSD).
Police said the officer who sent the original message had been dealt with “informally” and had carried out “developmental learning”.
In a statement to The Telegraph, Deputy Chief Constable Steve Cooper said: “Nottinghamshire Police’s Professional Standards Directorate (PSD) found one message posted on a WhatsApp group and took action immediately.
“Some of the words were crude and distasteful. One officer faced a gross misconduct hearing chaired by an independent legally qualified chair in January 2024.
“It was held in public at Nottinghamshire Police headquarters with both the media and members of the public in attendance.
“He was handed a final written warning by the independent legally qualified chair. After a thorough review by PSD, one other officer was subject to management intervention. No other officers were found to have committed misconduct.
“It is vitally important that the public are made aware of any action by an officer who falls below the extremely high standards we set and that is why these misconduct hearings are held in public.
“All officers have been reminded of the appropriate use of WhatsApp as a result of this misconduct hearing.”
Earlier this month, it was reported Nottinghamshire Police’s contact with Calocane before he killed Mr Webber, Ms O’Malley-Kumar and Mr Coates is being investigated by the independent watchdog.
At the time, a warrant was out for Calocane’s arrest after he assaulted a police officer in the city in 2021.
The victim’s families have also repeatedly raised concerns about the lack of toxicology tests carried out on the 32-year-old in the immediate aftermath of the attacks.
An IOPC spokesperson said that the investigation followed a voluntary referral by the force after it received complaints from the grieving relatives.