The odds on finding Caroline Dickinson's killer were infinitesimal.
Had it not been for her father's perseverance, a meticulous French judge, a conscientious US immigration officer and DNA testing, Francisco Arce Montez would not have been identified as the suspected murderer of the 13-year-old English schoolgirl.
This tragic, grisly story started at Pleine-Fougeres youth hostel near Mont St-Michel in Brittany on the morning of July 18th, 1996.
Four of Caroline's schoolmates woke to find the pretty blonde girl lying dead on her mattress. Police concluded that she had been raped and suffocated at around 4.30 a.m. Two of her friends thought they'd heard her having a nightmare.
Two days later the police arrested a homeless drifter who confessed to Caroline's murder. Then he withdrew his confession and was cleared by a DNA test.
Use of genetic evidence by criminal investigators was still in its infancy then, but Caroline's father, John Dickinson, asked Judge Gerard Zaug to test every adult male in Pleine-Fougeres, a village of 1,800.
Judge Zaug refused, claiming the tests were too expensive. Mr Dickinson took his case to the Rennes Appeals Court and won.
"I just did what I thought was right," he told me on the phone yesterday. In the autumn of 1997, 528 men reported to the Pleine-Fougeres town hall to have their mouths swabbed for DNA samples. When I reported the story for The Irish Times then, the local doctor told me he believed Caroline's murderer belonged to her school group.
Judge Zaug's replacement, Renaud van Ruymbeke, pursued the investigation more energetically. Before leaving Rennes in March 2000 to tackle financial corruption in Paris, Judge van Ruymbeke conducted more than 7,500 interviews and ordered 3,615 DNA tests.
He left his successor, Judge Francis Debons, a list of 70 wanted men. By this spring the wanted list had been sifted down to 48 men.
At the top was Francisco Arce Montez (51), a Spanish waiter who was arrested twice in the Loire valley in 1993 and 1994 for accosting schoolgirls at a youth hostel there.
"The French police found a hammer and a rope in his car," Mr Dickinson said. "And they let him go." In the 1980s Montez was convicted of three attempted rapes in Germany. He was briefly imprisoned in Spain for the attempted rape of a girl in 1997.
Then on April 1st a US immigration officer named Tommy Ontko from Detroit, Michigan, was flying home from holiday in Britain when he saw Montez's name in a newspaper.
"The name rang a bell," a French officer explained to Liberation. "When he got back, the American colleague had the professional reflex to run the name through the computer file, and bingo, he found Arce Montez imprisoned in Dade County, Florida, for sexual assault."
On April 12th two French gendarmes from the "Caroline unit" left Rennes for Florida. Montez refused to give a saliva sample, but US officials had an extra one on hand, which the gendarmes brought back to Paris.
The laboratory that compared the US sample with the sperm found on Caroline Dickinson found 14 identical markers, twice the number necessary for conviction in a French court.
Aside from expressing "a sense of tremendous relief", Mr Dickinson is circumspect as he does not want to prejudice legal proceedings. He is aware of media reports saying Montez was moved to a padded cell after attempting suicide on hearing of the DNA results. No one from Pleine-Fougeres contacted Mr Dickinson. "It's been a strange relationship," he said of the village made famous by his daughter's murder.
At the youth hostel a woman who did not wish to be named said the town's residents were also relieved. "We hope we won't see Pleine-Fougeres on television any more," she sighed. "It was bad publicity for us. Every time the press talked about the murder we received cancellations. Not a single English group has visited here since 1996."
