A West Midlands police officer found his parents murdered when he visited their home to check on them.
Avtar Kolar, 62, and his wife of 40 years, Carole, 58, were discovered at their home in Friary Road, Handsworth Wood, Birmingham.
A police spokesman said they had been subjected to an assault.
The couple, who had four children and eight grandchildren, last spoke to members of their family on Tuesday evening.
The family became worried after they were unable to contact the couple. Their son stopped by the house and found their bodies.
Forensic specialists are combing the area, while local CCTV footage is being analysed.
"We have 60 officers working around the clock to catch the offenders and I can assure the local community that we will catch the people who have done this horrendous crime," Det Supt Richard Baker.
He said that he was sure that the local community, which has been "very helpful and forthcoming", will have the "vital information" that will shed some light on the murder.
He also assured the community that officers would be present in the area to ensure safety and promised that the murderers would be caught.