She was discussing her role in the three-part series at its January premiere, which was organised by ITV Cymru Wales in partnership with RTS Cymru Wales.

Interviewed by Wales at Six anchor Jonathan Hill, Gallop explained how, in the series, she used DNA profiling to solve three high-profile murder cases, focusing on the horrifying deaths of Rachel Nickell, Stephen Lawrence and, in the premiered episode, the murder of Lynette White in Cardiff in 1988.

The last case had resulted in one of the UK’s worst miscarriages of justice in which five men, “the Cardiff Five”, were wrongly imprisoned but later released on appeal, two years later.

Gallop’s career started after she studied sea slugs at university – “they’re totally gripping”, she insisted. Her flair for detail led her into forensic science, which she discovered was a field “totally dominated by men”. Her experience allowed her to present forensic details in such a way that “lawyers could understand the evidence properly”.

The programme showed how she recreated White’s flat in the lab, which eventually gave clues to where blood DNA evidence could be found, more than a decade after the police investigation had originally drawn a blank.

She described herself as an optimist but, looking to the future, she is concerned that, when money is tight, the police struggle to fund detailed forensic investigations, and this could result in misleading evidence.

One of the Cardiff Five, John Actie, interviewed in the programme, was also in the audience, and he spoke about the lingering perception in the local community that, despite his successful appeal, there was “no smoke without fire”. But finding the real killer via DNA evidence cleared him once and for all.

He said: “Angela saved my life – I was completely finished until she came along.”