Two children found murdered with their mother at their home in Allerton Bywater, near Leeds, were stabbed to death, police said.
Shane Newman, six, and his sister Shannon, 11, died from stab wounds while their mother Geraldine Newman, 51, died from head injuries.
Hours after the bodies were discovered, the prime suspect for the triple murder - Mrs Newman's estranged husband Paul Newman - was found dead on cliffs at South Stack, off Anglesey.
Tributes were paid to the children, with Shannon described as "a bright, intelligent, enthusiastic, hardworking and caring student" and Shane as a "a caring, lovable young boy".
Detective Chief Inspector Warren Stevenson, West Yorkshire Police, said: "While our investigation into the full circumstances surrounding the deaths is ongoing, we can say that this appears to have been a domestic-related incident and we are not looking for anyone else in connection with it.
"The focus of our investigation is now on providing all the required information to the coroner so he can conduct inquests into the deaths.
"We have specially-trained officers supporting the families who are understandably distraught at the deaths of their loved ones. They have asked that they are allowed to grieve privately at what will clearly be a very difficult time for them.
"We are also liaising closely with the two schools that the children attended and offering them all necessary support.
"We appreciate that the shocking nature of this incident has impacted on the wider community and local officers will continue to provide suitable reassurance."
Helen Gilroy, acting head teacher at St Wilfrid's Catholic High School, Featherstone, said: "The students and staff of St Wilfrid's are deeply saddened by the news of Shannon's death.
"Shannon was a bright, intelligent, enthusiastic, hardworking and caring student. Shannon was very popular among her peers and will be greatly missed by all members of our community."
Sarah Spencer, head teacher at St Joseph's Catholic Primary, Castleford, said: "Shane was a caring, lovable young boy, full of fun, who enjoyed school and made many friends.
"He will be missed by all here at St Joseph's school and the whole of this close community. Prayers have been said in assembly and in local churches."
Police were called to the family's home in Beeston Way shortly before noon and found Ms Newman's body downstairs and the bodies of her daughter and son upstairs.
Mr Newman's body was discovered around 5pm near cliffs at the beauty spot which is about 160 miles away.
According to reports, colleagues of Ms Newman raised the alarm and a note was later found at an address linked to Mr Newman.
The mother was a branch manager for Wilko where she had worked for 23 years and a spokesman said she was a "loyal and enormously respected member of the team".
The retailer added: "This is tragic news and has devastated everyone who worked with Geraldine as well as impacting team members across the company.
"Our heartfelt thoughts and condolences are with her family, friends and colleagues at this very difficult time and everything is being done to support those team members who are affected by this tragic news."
On her LinkedIn page she described her children as "the light of my world".
Sean Firth, 44, and his 11-year-old daughter Chloe live across the road from the house. In tears, Chloe described how she played outside in the estate with the little girl.
She said: "I just feel really upset and really shocked. I never thought anything like this would really happen. They were really bubbly and nice and kind. She was just my friend."