An Austrian lab has been unable to match incinerated remains found in a dump with the DNA of dozens of trainee teachers Mexico’s government says were abducted and massacred in southwest Mexico, the attorney general’s office said on Tuesday. 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. 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.