A 26-year-old man could hold the key to solving the murders of two young people from Merseyside, police have said.
Mr Parle also goes by the name of Joseph
Kevin Parle, who is also known as Joseph, could help police investigating the deaths of Liam Kelly, 16, and Lucy Hargreaves, 22.
Liam was shot dead in Grafton Street, Dingle, in 2004, and Ms Hargreaves was shot at her home in Walton in 2005.
Mr Parle is white, about 6ft 5in with cropped ginger hair, a scar on the side of his head and a Liverpool accent.
Police believe he may be currently living abroad, but said they want to speak to him urgently.
Both the victims were shot dead
Detectives are working with the Serious Organised Crime Agency to pass on Kevin Parle's description to police forces in other countries.
Lucy Hargreaves, a mother of three, was shot at her home in Lambourne Grove, Walton, before petrol was used to set the house on fire.
Her 28-year-old partner and their two-year-old daughter escaped from the blaze in August 2005.
Liam Kelly was shot in the arm and chest in June 2004.
Police believed he was targeted in a drugs feud.
The appeal to track Mr Parle down will feature on the BBC's Crimewatch programme on Wednesday.