SHOCKED neighbours told how they have been left horrified by the senseless killings.
Police have confirmed that taxi driver Michael Atherton, 42, shot dead his 47-year-old partner Susan McGoldrick, her sister Alison Turnbull, 44 and her niece Tanya Turnbull, 24, before turning the gun on himself.
Officers stood watch over the entrance to Greenside Avenue in Horden, which remained cordoned off today.
A white forensic tent was erected outside the semi-detached house, where the bodies of the gunman and his three victims were found following the brutal rampage on Sunday night.
They remained at the murder scene throughout the day, while forensic experts built up a full picture of the tragedy.
Steve Patterson, a family friend, said he had talked to Michael Atherton’s brother, Chris on New Year’s Day.
Mr Patterson, 51, said: “Chris was saying that his brother wasn’t doing too well and had been suffering from depression.
“He said he was fed up with the way his life was going.
“I think he started feeling down after an operation he had on his heart in 2011.”
A neighbour said: “Micky did have problems with his heart, around summer last year Sue was telling me that Micky had just come out of hospital after an operation.
“I don’t remember him being too down about it though, he always said hello and seemed like a happy go lucky sort of person to me.
“They were just lovely. Sue lived for her family, she worked at the supermarket and all the rest of her time was sorting her family out.
“Laura still lived at home. She’s a blonde girl, really bonny.”
According to shocked people who lived nearby, Susan McGoldrick worked at an Aldi store.
A neighbour, who did not want to be named, said: “Sue was a lovely woman.
“She had two children, Laura, who is about 19, and Micky who is about 16 or 17.
“Micky was Michael’s son and Laura was to a different relationship.
“They were just a lovely couple. I don’t know why it’s happened and for it to be on New Year’s Day - it’s a hell of a time, everyone was in.
“Micky was a taxi driver and he liked shooting - it was his hobby so I knew he had firearms, it wasn’t a secret.
“Sue was very nice. She used to help me out - if it was raining she’d offer to go out for me and pick up things that I needed.
“I don’t know how long her and Micky were together for - it must have been a long time.
“They must have had some troubles in their relationship.
“I didn’t know anything until I woke up this morning.”
One neighbour, who lives in Greenside Avenue, said: “I was walking home from work at quarter past 12 last night and the first thing I saw was a guy running around covered in blood.
“He was shouting ‘someone’s been shot in the head’.
“I knew the family quite well. No-one can believe it’s happened.”
Another neighbour, who lives a few doors away from the scene of the killings, said: “We’re all in shock.
“I didn’t know anything about it until I woke up this morning and saw the cordon.
“It’s normally a quiet area - I’ve never known anything like this happen before.”