Forensic scientists trying to identify remains believed to belong to some of 43 missing students missing in Mexico have failed to find sufficient usable DNA in them, officials said on Tuesday.
Austrian scientists are using mitochondrial DNA from the samples for genetic testing, in an effort to identify 17 sets of remains sent by the Mexican government.
But the Mexican attorney general’s office said the University of Innsbruck reported that “excessive heat” had damaged the mitochondrial DNA in fragments of teeth and bones, “at least to the point that normal methods cannot be used to successfully analyse them”.
The university has offered to use one last technique to identify the remains, but says there is a risk the testing may destroy the samples without obtaining any useful information.
The university said it expected the testing to take another three months, but could not give an exact date for results.
The main risk is that the DNA extracted may be destroyed “without yielding any usable results”, prosecutors cited the university as saying.
Vidulfo Rosales, a lawyer representing families of the missing teachers college students, said prosecutors should have consulted the families of the missing students before making that decision.