Police have launched a fresh appeal for information about the murders of an elderly couple and their son, 25 years on from their deaths.
Harold and Mary Smith, both 72, and their disabled son, Harold Smith Junior, 47, were found dead at their home in Birmingham on 2 December 1992.
They had been bound at the wrists, subjected to a series of assaults and had stab wounds and cuts.
West Midlands Police said officers were reviewing all evidence in the case.
As nothing appeared to have been stolen, the motive for the attack remains a mystery, the force said.
The three were found dead at their bungalow in Overbury Close, Northfield, after they had not been seen for two days.
The couple also had a daughter.
Det Insp Ian Iliffe, from the force's cold case review team, said forensic opportunities in the light of advances in science would form part of the case.
He said: "There has been massive advances in DNA technology and we will be reviewing all the evidence we hold from 1992 to see if it sheds any light on new lines of enquiry."