Police have released an e-fit of a man they want to question in connection with an attempted robbery in a Derby park.
A 42-year-old man was walking his dog through Chaddesden Park at about 2045 GMT on 25 January when he was approached by four people.
One of them threatened him with a knife, but the group fled empty handed as a car approached.
The offender was described as white, aged 17 to 20, and 5ft 8in tall.
He was wearing a light grey hooded top with a dark jacket over the top.
The jacket had vertical stripes which were beige or brown. He was also wearing dark tracksuit bottoms and dark trainers.
Officers appealed for any witnesses to come forward.