In 1985?
Not that far out
In 1986, Richard Buckland was exonerated, despite having admitted to the rape and murder of a teenager near Leicester, the city where DNA profiling was first developed. This was the first use of DNA fingerprinting in a criminal investigation, and the first to prove a suspect's innocence.[62] The following year Colin Pitchfork was identified as the perpetrator of the same murder, in addition to another, using the same techniques that had cleared Buckland.[63]
I am sure that EP knew that the ability to use DNA in criminal cases was not far off .