UPDATE 4.50pm: The community of Portadown, Co Armagh is said to be in shock following the murder of an elderly couple.
Michael and Marjorie Cawdery, both aged 83 were found by relatives in Upper Ramone Park yesterday afternoon.
It is believed they were stabbed and may have interrupted a burglary - police are continuing to question a forty-year-old man.
Neighbour Alvin Winter says it is a devastating tragedy.
"An aged couple who were probably living there nice and quietly in retirement thinking that the're safe and sound and suddenly this happens.
"We always thought this was a safe quiet area but you never know now."
Update 12 noon:
A statement from the family of an elderly couple who were murdered in their home said: "The awful and incomprehensible events of Friday 26 May have deprived our family of two wonderful people, Michael and Marjorie, who were our father, mother, brother, sister and grandparents."
The elderly couple murdered in their home in Co Armagh, have been named.
Michael and Marjorie Cawdery, both 83, were discovered by a relative in their home in Ramone Gardens in Portadown yesterday afternoon.
It is thought they may have interrupted a burglary.
Detectives are continuing to question a 40-year-old man after an elderly couple were found dead in their in Co Armagh home.
He was arrested after the pair - thought to be in their 80s - were found dead by a relative in Portadown yesterday afternoon.
It is believed they had been stabbed in what police described as a "brutal" attack.
A forensic examination of the scene has been carried out and a murder investigation is underway.
Local Councillor Julie Flaherty told Q Radio News that Portadown is in shock, saying: "The residents and of course the family are going to need all our support in the weeks ahead."
Police and emergency services were called to the house in Upper Ramone Park around 3.40pm on Friday after the married couple were found dead by a relative.
PSNI Detective Superintendent Kevin Geddes said a grey Kangoo van, reg NJZ 6101, stolen from the couple's home was found around 5pm in the nearby Edenderry area.
"We are now treating this as a murder investigation and I would like to appeal for any information around it," he said.
He added: "It was a very brutal attack but I would like to reassure the public there are extra police patrols in the area and that will remain and we have made an arrest.
"That male was arrested close to the area where the vehicle was found in the Springfields area of Portadown."
The detective said officers were also investigating whether an attempt to break into a car parked in Upper Ramone Park at 12.20pm on Friday was linked to the murders.
Police cordons sealed off the house where the bodies were found and a large area of the street outside.
Shocked neighbours gathered along the street trying to gather information about what had happened.