A former FBI agent says a serial killer 'certainly' may have murdered several women in Ireland in the 1990s.
Convicted rapist Larry Murphy is a suspect in a number of the cases.
Ken Strange now works as a private investigator in California and is working on the Annie McCarrick case.
The American student disappeared without trace from Enniskerry, Co Wicklow, in 1993.
She's one of seven women who went missing without trace in Ireland in the 1990s.
Ken believes some of the cases may have been connected.
The former FBI agent recently visited Ireland to trace Annie's last movements.
It comes as Gardaí are carrying out searches in the Kildare region as part of the investigation into the suspected murders of several women over 20 years ago.
Ken hopes that might present a 'lucky break' in Annie's case.
Larry Murphy has been linked with these cases.
He was convicted of kidnapping, raping and attempting to murder a Carlow woman in the year 2000.
Mr Strange says he's rightly a person of interest in Annie's case.
The private investigator says he remains hopeful Annie's case will be solved - but he says it is a tough case to crack.
