Male students and staff at a high school in western France—527 people in total—were asked to give DNA samples beginning today as police search for the assailant who raped a teenage girl. The La Rochelle prosecutor's office said tests were expected to last from today through Wednesday at Fenelon-Notre Dame high school, where the 16-year-old was sexually assaulted Sept. 30 in a dark bathroom. Police recovered genetic material from the girl's clothing, but it had no matches in the national DNA database.
"This happened during the school day in a confined space," Chantal Devaux, the private Roman Catholic school's director, said in interviews with French media. "The decision to take such a large sample was made because it was the only way to advance the investigation." Summonses went out last week to 475 students, 31 teachers, and 21 others—either staff or males who were on campus at the time. Devaux acknowledged that all the results could come back negative, sending investigators back to the drawing board. The cost to analyze the samples is estimated to total $6,900. (Read more DNA evidence stories.)