Cold case reviews apply modern techniques to answer decades-old questions

The case file runs to at least 5,000 pages and occupies an entire room in a West Cork garda station, meaning the cold case review of Sophie Toscan du Plantier's murder could take well into next year to complete even with the deployment of new investigative techniques.

Sophie Toscan du Plantier was found battered to death outside her isolated holiday home in Toormore, near Schull, on December 23, 1996.

Garda cold case reviews thrust two violent murders of women in West Cork decades ago into the media spotlight this week.

On Tuesday, a detailed garda cold case review of the murder of a woman whose body was found in a remote wooded area near Innishannon more than 41 years ago led to the arrest of a 73-year-old man who was charged hours later with the murder.