Detectives are examining a knife marked with the first name of the killer of teenager Jodi Jones found near the site where she was murdered in Midlothian.
Luke Mitchell, Jodi's boyfriend, was ordered to serve at least 20 years in prison after being found guilty of killing the 14-year-old in June 2003.
The knife, marked with the name Luke, was found on waste ground in Dalkeith, half a mile from where Jodi was found.
DNA tests on the knife are said to have proved inconclusive.
Lothian and Borders Police have refused to say whether the blade matched injuries found on Jodi's body.
The knife was found by a member of the public in March and officers have been carrying out further searches in the area.
At his trial, Mitchell was found guilty of attacking Jodi, from Parkhead Place, Easthouses, hitting her on the head and body and compressing her neck, restricting her breathing.
He also repeatedly stabbed Jodi with a knife both before and after she died, inflicting wounds to her face, ear, mouth, breast and abdomen.
On the night of her death, Jodi and Mitchell, who was also 14, had been seen together at the start of a path known as Roan's Dyke.
Jodi's body was found in the woods half way along it.
Mitchell was jailed in December 2005 after being found guilty of killing her.
The murder weapon was never found, but five months after Jodi died his mother bought Luke a knife similar to one which he had lost.
He had engraved Jodi's initials on one side and a Satanic number on the other.
Mitchell has launched a number of unsuccessful appeals against his conviction and sentencing.