A woman disguised herself with a wig, fake goatee beard and heavy-framed glasses before killing her half-sister with a chicken-shaped casserole pot in Letchworth, a court heard today.

Yvonne Caylor, 53, also wore a hi-vis jacket and gloves as she tried to disguise herself as a man using clothes from a Baldock fancy dress shop, a prosecutor said at Luton Crown Court.

Ms Caylor, of Grove Road in Hitchin, is accused of murdering 26-year-old Nicola ‘Nikki’ Collingbourne in Ivel Court on Letchworth’s Jackmans estate on May 23.

Nikki’s body was found by two members of her family, wearing only underwear and lying in a pool of her blood on her kitchen floor shortly after 8pm the next day.

Prosecutor John Price QC told the jury of seven men and five women: “On the floor were shattered or broken pieces of ceramic, and they turned out to be the shattered fragments of a ceramic kitchen pot which was in the shape of a chicken. The pieces had been swept together.

“Both of Nikki’s wrists bore similar and deep incised wounds. A bizarre feature was that in her right hand she was holding a small hand-brush of the type that comes with a dustpan and brush set.”

Nikki also had a 4cm laceration to the back of the head, superficial parallel cuts to her neck and other injuries including bruising to the face.

Mr Price said experts set to testify later in the trial had been unable to ascertain the exact cause of death, but that it appeared the attacker had lifted the pot with both hands before crashing it down on Nikki’s head from behind.

“This was an unnatural and violent death and it was caused by someone other than Nikki,” said Mr Price.

“The blow to the back of the head had split the skull to its full thickness.”

Mr Price alleged that Ms Caylor murdered Nikki after being charged with burgling her half-sister’s flat and attempting to pervert the course of justice.

He suggested that aspects of the scene such as the wounds to the wrists and the brush in Nikki’s hand indicated an attempt to stage a suicide.

“If that is the case it was very incompetently done,” he said.

“For example, if she had been holding the brush, it would have been expected to fall from her hand before she hit the ground.

“The wounds to her wrists had an appearance indicating they had been applied only shortly before her death – she was unconscious, but still alive.”

Nikki’s blood was found in the kitchen, the bathroom and the hallway, including on the main door handle.

A towel and a bucket were found in the hallway, with the bucket containing a small knife and a piece of flesh about the size of a five-pence piece.

The court was shown CCTV footage from Ivel Court that showed a heavy-set figure in a hi-vis jacket entering the flat at about 8.30am and leaving shortly before 12 noon on May 23.

“At first sight the visible facial hair would suggest to the viewer that this is a man,” said Mr Price.

“As you saw, that person went directly to the door of this particular flat and used the letter box to knock on the door, more than once. The person waited for quite a while before the door was opened.

“It’s somebody quite short in stature, of slight build – but even though it’s late May that person was wearing gloves. The person had reddish hair, a similarly coloured goatee or ‘Van Dyke beard’, and was wearing heavy-framed spectacles.

“These images show very obviously that the hair and the beard are fake, so this person is not necessarily a man. And if the hair and beard are fake, so too might be the spectacles, in that the person doesn’t need them.”

The footage showed the intruder apparently forcing entry to Nikki’s flat.

“The door is opened from within,” said Mr Price. “The only person in the flat at that time was Nikki.

“Within four seconds she tries to close it again, on seeing the person at the door – but the person forces an entry.

“This is obviously a false beard and wig, so the disguise’s purpose may not have been to deceive Nikki, but to try to conceal the intruder’s identity from the cameras. That would indicate prior knowledge of a CCTV system.

“The bath towel found in the hall suggests Nikki had wrapped it round herself when she opened the door.

“After the intruder went in, the door momentarily opened again before shutting a second time. A bloodstain was found on the interior door lock, and injuries such as cuts to the hands might indicate that Nikki was attacked immediately on opening the door.”

The figure was shown leaving the flat with a bag that they had not entered with. Not all parts of the chicken-shaped pot were found when police reassembled it, and Mr Price suggested there was no way they could have left the flat apart from inside this bag.

The prosecutor told the court that two witnesses from the Harlequin Costume Hire shop in Baldock – Susan Jones and Richard Rosendale – recalled the defendant enquiring about fancy dress costumes during April, saying they were for herself and ‘a man’.

Neither could recall the exact date of the visit, Mr Price said, but telephone evidence indicated it was April 22. Both Ms Jones and Mr Rosendale picked out Ms Caylor during identification procedures on August 25.

“We submit that on the afternoon of April 22 this year this defendant was in Baldock trying on wigs,” Mr Price concluded.

The prosecutor described in detail how the relationship between Yvonne Caylor and Nikki Collingbourne – who shared the same father, and briefly lived together in the United States about four years before Nikki’s death – had broken down acrimoniously, particularly after Nikki let Yvonne live with her at Ivel Court for a short time after the older sister’s return to the UK last year.

The court heard that relatives first became concerned about Nikki when she failed to collect her mother Rena Hibbert-Jones from Stevenage’s Lister Hospital – where she had been receiving treatment – on May 23.

Rena suffered from a severe respiratory condition, and Nikki was active in helping care for her. Rena has died since Nikki’s death.

Yvonne Caylor denies murder. The case, which is expected to last about two weeks, continues.