Police have released a picture of a British teenager believed to have slashed his parents' throats with a knife.
John and Jill Sumner suffered serious stab wounds and both are recovering in hospital after undergoing surgery.
Sven Sumner, 18, is thought to have driven off in the family's blue Vauxhall Nova car.
Police were called to the family home, in Milford, near Stafford, after a 999 call and discovered Sven was missing along with the car.
During a police interview, Mr Sumner, 66, and his 53-year-old wife told detectives they had been stabbed by their son during an argument.
Officers removed a collection of knives from the house.
Police say they are unable to disclose the exact motive for the attack and have urged Sven to contact them.
"We would urge him to get in touch with us urgently and if anyone has any information on his whereabouts to contact police," said a police spokesman.
"We would also like to say to Sven that if he has any problems, he can talk to us and we will try to help him out," he added.