The "World's End Murder Trial" collapsed this morning when Judge Lord Clarke upheld a defence motion and decided that the Crown had failed to put forward a sufficient case for the prosecution to proceed further and that there was insufficent evidence to convict.
Angus Sinclair had denied raping and killing Christine Eadie and Helen Scott, both 17, in 1977 after a night out at Edinburgh's World's End pub.
Last week forensic scientist Martin Fairley told the court that tests were carried out in mid-1995 using the latest DNA profiling techniques. He told the court though that these tests could only narrow the DNA profile down to one in 2,400 of the male population.
The tests, STRs for "Short Tandem Repeats" or "Quads", only examined four areas of DNA compared with the 10 areas examined today.
He also told the court that Christine's blood could not reveal a DNA profile because it had been kept too long but a result was obtained from her hair.
Angus Sinclair had lodged a special defence blaming his brother-in-law Gordon Hamilton for the murders.
Sinclair was convicted and jailed for life in 2001 for the rape and murder of Glasgow teenager Mary Gallacher 22 years earlier. New DNA evidence had linked him to the crime.
He was also convicted of the culpable homicide of seven-year-old Catherine Reehill in 1961 for which he served six years.
Sinclair also has convictions for three rapes and for other sexual offences for which he was convicted at The High Court in Edinburgh in 1982.
Police believe he may have links to several other unsolved murders which date back to the 1970s.