The 43 Missing Students Are Not Alone. Mexico's Justice System Is Broken.

Even in a country hardened by nearly a decade of deadly criminal conflict, the Ayotzinapa case stands out: 43 students forcibly disappeared during the night of Sept. 26, 2014, allegedly at the hands of municipal police in league with a local drug gang. President Enrique Pea Nieto promised that this horrific crime, above all, would not go unpunished. "After Iguala," he declared , naming the city where the youths went missing, "Mexico must change."

Nineteen months later, the case has generated much controversy but little change. A group of international experts backed by the Organization of American States, invited by the government to assist federal investigators on behalf of the victims' families, has departed after issuing a scathing 600-page report citing evidence that suspects were tortured, promising leads left unexplored, contradictory forensic reports ignored and key evidence mishandled -- perhaps planted -- in an apparent effort to close the probe as quickly as possible.

Meanwhile, the president's proposed security reforms -- most notably a plan to fold more than 1,800 municipal police forces into 31 statewide corporations -- remain largely unfulfilled. A national violence prevention program -- touted by candidate Pea Nieto as the answer to his predecessor's discredited war on drugs -- has seen its already meager funding slashed by about 20 percent since 2013.

Despite the deployment of federal troops and police to the state, fragmented gangs continue to wage brutal turf wars.

The bloodshed, tragically, has not stalled. Last year's homicides rose slightly (8 percent) in the country as a whole and dramatically in certain states, such as Guerrero, where murders surged by 30 percent. Despite the deployment of federal troops and police to the state, fragmented gangs continue to wage brutal turf wars to control drug trafficking and illegal rackets like extortion and kidnapping. The disappearance of the 43 student teachers is far from the only unsolved case. Authorities -- under pressure from the relatives of other missing persons -- have discovered dozens of clandestine graves near the city of Iguala containing at least 140 bodies.

No wonder citizens show little faith in the country's law enforcement institutions. Not only do few Mexicans trust their municipal police (36 percent), according to official surveys , less than half express confidence in state prosecutors or investigators (42 percent), state police (43 percent) or judges (46 percent). Federal prosecutors (trusted by 49 percent) and police (56 percent) fare only a bit better.

President Pea Nieto could still put his country on track to end the self-perpetuating cycles of violence, corruption and impunity that have turned certain regions into virtual war zones. But to do so, the president must address the "incredulity and distrust," which, as he himself has stated, are undermining the law and order essential to assure that his economic reforms generate the promised prosperity.

The government should start by recognizing that the experts' report not only raises serious questions about the Ayotzinapa case but also about the justice system in general: the overreliance on confessions to determine guilt, the lack of independent forensic services, the burden of unnecessary bureaucratic procedures, the inability to weigh the validity of evidence or to analyze context, the tendency to measure success based on the number of arrests (often on flimsy evidence that is later dismissed) and the failure to investigate the intellectual and material authors of crime.

President Pea Nieto can still turn tragedy into a catalyst for change, but he cannot do so alone.

The Mexican government did the right thing by inviting international experts to assist in a case that has come to symbolize the horrific brutality of criminals that operate in complicity with some state agents. Their job is not over. President Pea Nieto can still turn tragedy into a catalyst for change, but he cannot do so alone. To salvage the Ayotzinapa case -- and overcome the crisis of confidence that threatens the government's own reform agenda, Mexico should extend and expand the experts' mandate to address the systemic flaws that have made incompetence, complicity and corruption sadly synonymous with the country's own institutions of law enforcement.