Police investigating the murder of a teenager more than 25 years ago have ruled out five new "persons of interest" after negative DNA tests.
Natalie Pearman, 16, was found dead in a lay-by at Ringland, near Norwich, on 20 November 1992.
DNA recovered from the scene could hold the key to solving the case, Norfolk Police believe.
Five men identified after a fresh appeal last year have now been ruled out as suspects.
Police are continuing to appeal for witnesses to come forward.
Natalie's body was found at 03:50 GMT by a lorry driver en-route to work. She was last seen alive in Rouen Road, Norwich, at 01:15.
Post-mortem tests found Natalie, who had been working as a prostitute, had been suffocated and police said there were signs of sexual activity shortly before her death.
Police have DNA-profiled nearly 700 men and interviewed more than 4,000 people in the case.