A nursing home has ramped up security after a grandfather walked out of the unit and was later found dead in a field.
Kevin Herbert, 58, left Brookview Nursing Home in Holmley Lane, Dronfield, on the evening of January 22, 2014.
He was reported missing - prompting a major search - before a member of the public found Mr Herbert's body near Sheffield three days later.
Yesterday, an inquest heard it is believed Mr Herbert, who was also known as Charlie, walked out of the premises through a fire exit.
Giving evidence at Chesterfield coroners' court, agency nurse, Ralston Shawsmidth, said he was working his first night shift at the home when he realised Mr Herbert was not in his room.
He told the inquest: "I wasn't concerned because in a nursing home a lot of people move around and you usually find them somewhere else.
"We went to look for him but he couldn't be seen him so we became concerned and contacted the police."
Mr Shawsmidth said a fire exit, located close to Mr Herbert's room, was open.
Coroner James Newman asked: "Was it your presumption he'd gone out that way (the fire exit)?"
Mr Shawsmidth replied: "Yes."
Janet Porter, a care assistant at the home, said the fire exit was fitted with an alarm which, when sounded, could not be heard around the whole of the large site, which caters for nearly 60 people.
Referring to 2014, Kate Showanska, a nurse and deputy manager at the home, said residents, including Mr Herbert, had access to keys so they could walk through patio doors in their rooms and into the garden.
Mrs Porter added: "We didn't tend to go around checking all the locks but we'd make sure they (the doors) were closed."
Ms Showanska said: "Now, all fire doors and all patio doors are connected to the nurse call system."
This means that staff are alerted if a resident tries to leave the building through one of the doors, the court heard.
Earlier this year, the Care Quality Commission rated Brookview Nursing Home as 'good' overall but found 'the service was not always safe'.
Ms Showanska told the inquest Mr Herbert was known to walk around the facility and she believed he had the mental capacity to make his own decisions.
Mr Newman asked her: "Did Mr Herbert ever express a desire to leave the home?"
Ms Showanska replied: "To my knowledge, no."
Dad-of-one Mr Herbert, of Emmett Carr Close, Renishaw, suffered from the rare brain disorder progressive supranuclear palsy, which affects balance, vision and speech.
Following an assessment, he was admitted into the home at the end of December, 2013, to receive temporary care while Dorothy Ward, his partner of 20 years, recovered from an operation.
Pathologist Dr Danesh Taraporewalla said former miner Mr Herbert died of ischemic heart disease with hypertension and hypothermia contributory factors.
The inquest continues today.