Just hours after stabbing his boss to death a university worker posted a chilling picture that said “stand up to bullies, then kill them”, a court heard.

Mobile phone data showed David Browning was still in the area of Jillian Howell’s home in Brighton when he posted on Facebook the shocking cartoon image of someone being stabbed.

Browning had stabbed Ms Howell 15 times between 11pm and midnight on October 25 then scrawled the word “bully” on her forehead in marker pen, the jury at Hove Crown Court was told.

Officer in the case Detective Constable Michael George told the court that mobile phone data analysed from Browning’s phone showed he was in the vicinity of Ms Howell’s home in Sandgate Road at the time he uploaded the temporary profile picture.

He said: “At approximately 4.30am a temporary profile picture was uploaded to Mr Browning’s Facebook account with this image that said ‘stand up to bullies – then kill them’.

Browning left letters blaming Ms Howell and accusing her of bullying and belittling him at work.

In the letters read to the court Browning wrote that his work place at Brighton University “felt like a war zone”and said Ms Howell had a “reign of terror” over staff and called her a “really horrible person”.

However, in text messages he sent to Ms Howell in the months leading up to her death he told her he adored her and appeared to be growing increasingly infatuated with her.

In one letter left at Ms Howell’s home he wrote: “I did this thing to rid this place of a really horrible person who was the cause of all this.”

Then in a letter addressed to his wife Deborah and children Mark and Remmie he said: “I’m so sorry that you are having to go through this.

“I felt I could not go on.

“My office felt like a war zone with a manager having a reign of terror over colleagues. I know what I have done is wrong.”

The court has heard he bought a shotgun and went to Ms Howell’s home for dinner. He then stabbed her in the back, neck and front, the jury was told.

Browning, 51, of Willow Drive, Seaford, admits manslaughter by diminished responsibility claiming his depression led him to suffer a brain abnormality at the time he stabbed Ms Howell. He denies murder.

The trial continues.

Bid to change pension details

Obsessed and “jealous” David Browning sent a stream of increasingly affectionate messages to his boss before killing her, the court heard.

David Browning told his manager Jillian Howell in the University of Brighton’s payroll department he “adored her” as she tried to counsel him through depression and the loss of his father.

Hove Crown Court heard how Ms Howell sought help for Browning from the university’s occupational health department in September – but just days later Browning bought a second hand 12 gauge shotgun and the lock knife he used to stab her 15 times.

Text messages between the pair were read to the court. On June 8, after the pair went for a social drink at the Signalman pub in in Ditchling Rise he sent her a message to say “I adore you personally and professionally”.

In another message he said “what a wonderful lady you are” bones in her voice box, suggesting she may have been grabbed around the neck during the attack, the jury was told.

Cuts and grazes to Ms Howell’s hands showed Ms Howell had tried to fight off her attacker.

She concluded: “Her death was as a result of a combination of stab wounds to the neck and chest. “The stab wounds have required at least a moderate degree of force.”

On August 4, Browning said: “I’m glad we can trust each other. You are more than just my boss and I think you know that.”

However Browning became controlling, obsessed and jealous, believing Ms Howell was in a relationship with friend and former Worthing mayor Sean McDonald.

Browning tried to change Ms Howell’s pension to frame Mr McDonald for her murder the court was told.

Pensions administrators received notification claiming she wished to change the beneficiaries of her pension in the event of her death from family members to McDonald the day after her death.

However the signatures on the forms did not match earlier signatures, Hove Crown Court was told. Alan Gardner prosecuting told the jury: “It is the crown’s case that David Browning completed that form and sent it to the pension people.”

Browning’s defence barrister Graham Trembath QC said he did not dispute sending the fake forms. Browning also left a letter written to Mr McDonald.

In it he said: “Only a paedophile would think a man in his fifties should be out with a woman much younger. You are what the police would call a wrong ’un.”

Opening the case on Monday, Mr Gardner told the jury that Browning had formed an “intense attachment” to Ms Howell before becoming “controlling, obsessed and jealous” when he believed she was dating Mr McDonald.

Browning claims his depression and grief over the death of his father caused a brain abnormality.

But Mr Gardner said: “This was a premeditated, cold-blooded murder of a woman in her home by a man she trusted as a colleague and a friend. A man she was trying to counsel since the sad loss of his father.

"He killed her out of anger rather than an uncontrollable urge caused by his depression. He planned to kill her several weeks before and made careful arrangements to carry it out."

She ‘tried to fight’

Moderate to severe force would have to have been used to kill Jillian Howell a post mortem concluded.

Home Office pathologist Charlotte Randall found that Ms Howell had suffered eight knife wounds to the neck, a further six to her front and one to her back.

She said the most serious injury was fatal “transection of the jugular vein”. She also suffered broken bones in her voice box, suggesting she may have been grabbed around the neck during the attack, the jury was told.

Cuts and grazes to Ms Howell’s hands showed Ms Howell had tried to fight off her attacker.

She concluded: “Her death was as a result of a combination of stab wounds to the neck and chest. The stab wounds have required at least a moderate degree of force.”