A nurse working at a care home described how a man calmly smiled at her moments after slitting his grandmother's throat.

Maria Stanciu told how Antony Jennings said he had killed his 94-year-old grandmother Ruby Wilson when minutes before she had seen them laughing and drinking tea together.

Jennings, 33, is accused of murdering great-great grandmother Mrs Wilson with a bread knife at Forest Place Nursing Home in Buckhurst Hill, Essex on November 29 last year.

Ms Stanciu, from Romania broke down in front of a jury at Chelmsford Crown Court today (tue) as she described how Jennings approached her after the horrifying attack.

She told jurors how he tapped on her shoulder, adding: "He said, 'I'm sorry Maria I just killed my Nan'. I asked him if he's joking. He said, 'Come'.

"He was just looking at me, he was calm. He was looking at my face and he was smiling."

The court heard how she walked into the elderly woman's room to find her in a chair with her hands on the arm rests, with blood on her chest and down her neck.

Jurors heard that she checked Mrs Wilson for a pulse but found no sign of life.

Ms Stanciu, who had worked at the home for 18 months, said: "I left the room. I asked him if he knew what he had done."

She told jurors Jennings said to her: "She's in peace, she's not suffering any more. She's not in pain any more."

Ms Stanciu added: "I went running towards the manager's office. I told her what happened and that she needed to call the police.

"He was just walking in the corridor."

Jennings sat in the dock wearing a blue Adidas tracksuit top, surrounded by one dock officer and three hospital staff.

Jurors heard how, before the attack, Mrs Wilson and her grandson had been in the care home lounge.

Ms Stanciu said: "They were sitting together at the table. My carer offered them a cup of tea.

"They were laughing, talking to each other."

She added: "Ruby was happy to see him. He seemed happy as well."

Dorian Lovell-Pank, representing Jennings, asked Ms Stanciu what she meant when she later told police in a statement that Jennings was "on another planet".

She said: "His face was towards me but at the same time his mind was somewhere else."

Jennings, from Ilford, London denies murdering Ms Wilson but entered an alternative plea of guilty to manslaughter on the grounds of diminished responsibility.

The trial, which is presided over by Judge Patricia Lynch QC and is expected to last up to three weeks, continues.