A male resident at the same care home is being held on suspicion of murder and police confirmed that the victim and suspect knew each other. A murder investigation has been launched by police after the woman in her 80s died after being shot at a care home in Walton-on-the-Naze. Officers were called to the home just before 9am on 28 December.

Emergency services were called to the home just after 9am following reports that a woman had been seriously injured, police said. Officers and ambulance crews attended, but the woman died.

DCI Simon Werrett said: "It is an unusual investigation. Both parties involved are residents in the care home. We are speaking with members of staff to find out if they witnessed any unusual behaviour this morning."

Speaking outside the home, he said: "The weapon has been recovered from the man's possession ... Members of staff stepped in to remove the weapon from the man."

Scene of crime officers were seen searching a downstairs bedroom, but Werrett, who is leading the investigation, confirmed: "The incident did not take place in a bedroom. It took place in a communal area." A scene guard has been put in place at the premises while forensic searches are conducted.

A man who lives opposite the care home said he heard "two or three bangs" but put it down to military testing on MoD land nearby. "It was probably the gun," he added.

Local Essex resident John Knights said security was tight at the care home: "My mother had to go into Delamer about two years ago and I can tell you that it was quite tricky to get in and out of there.

"Security was tight. You couldn't just go up to the building and get in," he told the Belfast Telegraph. "You needed a security code to get in. It had electronic keypads on the door, so to get inside you needed to know those.

"Whoever was responsible must have known the code."

Douglas Carswell, the Ukip MP for the area, said he was "very shocked" by the news, adding that Walton-on-the-Naze was usually a peaceful place.

He told the Press Association: "If you have got a loved one in a care home, you expect them to be safe. People need to know the exact circumstances of what happened, it is extremely disturbing.

"Walton-on-the-Naze is supposed to be one of the most peaceful and tranquil places there is – elderly people want to be in a peaceful and tranquil environment. Of all the places you expect this to happen, this is the last."

Anyone with any information is asked to contact Essex Police on 101. They can also email SCDappeals@essex.pnn.police.uk.

Delamer House is a privately owned home run by Novocare Ltd and has room for up 57 elderly residents, according to the Clacton Gazette. It costs £475-£575 a week for a single room and £400-£495 per person for a shared room.

The homes offers specialist care in areas including Alzheimer's, epilepsy, head and brain injuries, deafness, motor neurone disease, multiple sclerosis, Parkinson's disease, stroke and visual impairment.