An Austrian lab has been unable to match incinerated remains found in a dump with the DNA of dozens of trainee teachers whom Mexico's government says were abducted and massacred in the country's southwest, the attorney general's office said on Tuesday.
The 43 students went missing on Sept. 26 in Iguala, a city in the poor southwestern state of Guerrero. The government says the students were abducted by corrupt police working for a local drug cartel, which it said incinerated their bodies at a nearby garbage dump.
So far, experts have identified the remains of just one of the group.
The brazen attack sent shockwaves through Mexico, where more than 100,000 people have died in drug-related violence since 2007, highlighting the mix of impunity, corruption and drug gangs that has blighted Latin America's No.2 economy.
It also sparked President Enrique Pena Nieto's worst crisis, forcing him to admit he hadn't paid enough attention to security as he focused on driving through economic reforms.
The Innsbruck Medical University's forensics institute told the Mexican government the rest of the available remains were so badly burned it was impossible to take a usable DNA sample.
Nonetheless, the institute, in a letter, offered to use a new technique, known as massive parallel sequencing, to test the bone fragments in the hope of eventually identifying a match.
"We can't offer an estimate on how successful this will be but the technical specifications of MPS are the most promising of any genetic molecular identification method that exists," it said in the letter, cited by the attorney general's office.
The new tests should take three months but there was no set time frame, the office added.
The Austrian forensics team is considered a world specialist in identifying damaged remains through DNA testing. In 2004, the lab reconstructed DNA profiles of victims of a tsunami in South Asia whose bodies had been rotting in extreme heat and humidity.