The appeals court in Rennes removed Gerard Zaug and entrusted the case to Judge Renaud van Ruymbeke, one of the country's best-known investigating jurists.
The court also ordered police to carry out systematic genetics tests on all men aged 15 to 35 in Pleine-Fougeres, the Brittany village where the 13-year-old was strangled on 18 July, 1996 while on a school trip from Launceston, England.
Van Ruymbeke, who has gained a reputation for tenacity in his investigations of political scandals, was due to meet investigators of the paramilitary gendarmerie to discuss the case.
"We are very happy with what happened today. New avenues will be explored," Caroline's father told reporters.
He said Van Ruymbeke told him that new methods of investigation would be used. The Dickinsons had sought to have Zaug and the gendarmerie taken off the case, arguing that they had made several mistakes.
They filed a fresh lawsuit last month to demand further investigations, with a formal application for wider genetic testing, a public appeal for witnesses and the linking of the investigation with another probe into a sexual attack at a youth hostel a few miles away on the same night.Reuse content