Beryl ‘Bez’ Purdy, 86, was found suffering serious injuries at the property in Broomfield, Somerset, at around 5.45pm on Monday.
Police were responding to reports of a burglary in progress when they discovered the wounded pensioner.
Officers and paramedics desperately tried to save her, but Beryl sadly died at the scene.
The force announced a man in his 30s was arrested before being sectioned under the Mental Health Act.
They confirmed the suspect was reported missing from a mental health unit shortly before Beryl was found dead.
Avon and Somerset police said they had made a mandatory conduct referral to the Independent Office for Police Conduct (IOPC).
The quaint village of Broomfield has been rocked by the loss of Beryl, who was fondly known by locals as Bez.
Flowers have been left near the scene as locals grieve the tragic pensioner, who was a devoted member of the community.
One tribute read: “Bez – there are no words. Our thoughts are with you and your family.”
She was well-known among residents after serving for 20 years as church warden of St Mary and All Saints church.
The mum, who is understood to have cared for her husband Peter who suffers from severe mobility problems, was also listed as the booking secretary of Broomfield Village Hall.
One resident said: “Bez was a charismatic person and a devoted member of our community, having been our church warden for as long as we can remember.”
Another added: “Bez was a stalwart of the local church where she had been a warden.
“It is terrifying to think something like this could happen in such a beautiful out of the way spot.
“You couldn’t imagine somewhere farther from crime ridden city streets. It is so idyllic and peaceful. Or at least it was. It will take us a long time to get over something like this.”
Neighbourhood Chief Insp Justin French said: “Our thoughts remain with the family during this incredibly difficult time and they are being supported by specially trained family liaison officers.
“Incidents of this kind are rare and understandably can cause concern among the community.
“Our officers will be out and about conducting reassurance patrols and we encourage people to speak to them with any questions and concerns they may have.
“The public can expect to see an increased police presence in the area for the next few days.”
Avon and Somerset Police said: “A man in his 30s was arrested in connection with the incident.
“He was assessed by a mental health professional and was deemed not fit for interview or to be detained in police custody.
“He was sectioned last night under section two of the Mental Health Act and has been transferred to a secure mental health unit.
“Detectives from MCIT continue to carry out a full and thorough investigation and the public can expect to see an increased police presence in the area for the next few days.”