Jed Allen is said to be related to the victims, who are all from the same family
Police have released the name of a man wanted in connection with the deaths of a man, a woman and a girl, found at a house in Oxfordshire.
Thames Valley Police are looking for Jed Allen, 21, thought to be a relative of the victims found in Didcot on Saturday.
University Parks in Oxford has been closed while police search the area.
A woman, 48, a man, 44, and a girl, six, were found at the house in Vicarage Road at about 20:20 BST.
The three, who were members of the same family, were pronounced dead at the scene.
Det Supt Chris Ward said Jed Allen had a tattoo on his left hand of a spider
Det Supt Chris Ward of Thames Valley Police said Mr Allen was believed to be related to the family.
He told the BBC searches for Mr Allen were taking place in university grounds in Oxford. Allen formerly worked as a university grounds-keeper.
An Oxford University spokeswoman confirmed that University Parks had been closed at the request of Thames Valley Police.
He is described as being 6ft (1.82m) tall, of large build, with a tattoo of a spider on his left hand.
The deaths are being treated as suspicious but no arrests have been made, police said.
Det Supt Ward said: "It's very important we locate him as quickly as we can.
"I do not believe there are any dangers to the wider community of Oxfordshire. However, given the nature of what we are dealing with, it's important that we find him as quickly and as safely as possible."
He said the families of the victims had been informed and were being cared for by specialist officers.
Post-mortem examinations are due to take place later to determine the cause of death but police said they did not believe a gun was involved.
Det Supt Ward said: "As a result of this ongoing search for Jed Allen there will be a number of overt searches both within Didcot and Oxfordshire as well.
"I appreciate that's difficult for people and, while I want to reassure them, they will see a number of police officers and a lot of overt activity in relation to that."
A police cordon is in place at Vicarage Road, which has been closed to all but residents since the bodies were found on Saturday
Police said a neighbour first called police to the house, where the family is believed to have lived for about two months.
Investigating officer Det Ch Insp Simon Steel of the Thames Valley Police major crime unit, said: "This is a tragic incident and our thoughts are with the loved ones of the deceased. A scene watch is in place in Vicarage Road, which is currently closed with access to residents only.
"I understand this incident will have an impact on the community and residents will be concerned. As you can understand, we are in the early stages of this investigation, but we will work hard to make sure the community is kept updated when we can."
Thames Valley Police is appealing for anyone who saw or heard anything suspicious in Vicarage Road on Saturday evening to contact it.