MEXICO CITY -- After police found 49 dismembered bodies strewn on a Mexican highway leading to the Texas border, it took the army just a week to parade an alleged drug trafficker before journalists as the man who purportedly oversaw the body dump.

Yet two months after the grisly discovery in Nuevo Leon state, authorities have not identified a single victim.

The 49 bodies now appear headed for an increasingly common fate in this drug war-wracked country: They could join the growing ranks of the unidentified dead.

That group has become legion as nearly 16,000 bodies remain unidentified, says the National Human Rights Commission, an independent government agency. In total, 24,000 people have been reported missing. Many say the country's police are simply overwhelmed by the number of drug war casualties as they struggle with poor forensic capabilities and the reluctance of some witnesses and victims' relatives to help.

That apparent futility is drawing increasing criticism from Mexicans weary of the government-led offensive against drug cartels, who are also fighting among themselves. The violence in total has claimed at least 47,000 victims since President Felipe Calderon launched his anti-cartel campaign in late 2006.

"The level of violence we're living with reflects the critical condition our institutions are in, and it reveals a corrupt government," said Blanca Martinez of the Fray Juan de Larios human rights center in the northern border state of Coahuila. Hundreds of people have gone missing in Coahuila since 2009, when violence started to erupt in northeastern Mexico.

The most recent discovery of corpses shows just how hard it is to put names to often heavily mutilated bodies.

Although the 49 corpses all lacked heads, hands and feet, police performed DNA tests on them and compared the results, without luck, to hundreds of Mexicans reported missing.

The authorities captured Daniel Elizondo, the alleged cell leader for the hyper-violent Zetas drug cartel, and pinned the atrocity on him. But he and two other suspects arrested in the case apparently haven't offered any information that could help investigators. The army has said Elizondo claims he was given the bodies by someone else.

The bodies of the 43 men and six women remain at a morgue in the industrial city of Monterrey where they're marked "N.N." – the Spanish initials for "No Nombre," or No Name. They've also been given numbers as IDs, a state police spokeswoman said. Authorities believe the bodies were signs of yet another battle between the Zetas and their rival Gulf and Sinaloa cartels.

Now it's up to the lead investigator to decide how long the bodies will remain at the morgue before they're wrapped in blankets and buried side by side in common graves in cemeteries throughout Monterrey's metropolitan area, said the police spokeswoman, who would not allow her name to be used under official policy. The bodies can stay in the morgue for a maximum of four months. By custom, Mexicans usually bury their dead within 48 hours.

Anguished relatives of the missing said they suffer in limbo awaiting any information about their loved ones.

"When they took my son, they destroyed me," said Maximina Hernandez, a 44-year-old maid from the Monterrey suburb of Santa Catarina whose police officer son was taken by gunmen minutes after ending a work shift in 2007. "The only thing I ask God is for some news, to know where he is. But there is no progress; there is nothing."

Hernandez has joined other people with missing relatives to push authorities to investigate the cases but said she's been disappointed by the results so far.

She said police took DNA samples from her and her son's father but never followed up on her suspicion that her 23-year-old son's commander was involved in his disappearance. Last year, authorities detained the police commander along with more than 40 Santa Catarina police officers for allegedly working for the Zetas.

Luis Garcia, an investigator with the National Human Rights Commission, said the number of unidentified bodies continues to grow, as has the number of missing persons. The commission listed 8,898 unidentified bodies from 2000 to 2005; that number had since jumped by 80 percent as of June. The number of missing people reported in the earlier period, 5,397, has grown even more dramatically, by nearly 350 percent.

No one knows exactly how many of those unidentified bodies were killed in drug-related violence or how many people are missing at the hands of cartels because such a study has never been done, Garcia said.

"There needs to be an investigation in each case, to put a first and last name (on each victim) so that there is no impunity," he said. "The issue here is that there is no effective investigation."

Government efforts to tackle the monumental problem have produced mixed results. Calderon has tried to reform and professionalize the federal police force, which has tripled in manpower to 35,000 officers, but has had little success improving local and state forces. The government proposed creating a national database with information on missing persons that could be accessed by investigators in all 32 states but is still trying to get it up and running.

Crime victim relatives have long complained that requests for help are often ignored and say it's not uncommon for them to be harassed to stop pushing for an investigation.

Unlike Nuevo Leon, the majority of Mexico's 32 states don't even have the technology to do DNA profiles, and few investigators are trained on how to process a crime scene.

In many cases, overwhelmed police have to identify dozens of bodies, dumped in abandoned mine shafts, left in the middle of busy avenues or buried in mass graves.

In Durango state, authorities found five bodies in a clandestine mass grave in mid-July, raising the total of corpses unearthed in the state since April 2011 to 336, said state prosecutor Sonia de la Garza. More than 600 families have turned over DNA samples to state authorities, who have to send them to neighboring Chihuahua state for processing.

Police around Durango initially were using backhoes to dig out bodies from mass graves before investigators intervened because that was destroying evidence.

"The fact that so many bodies remain unidentified tells you about the enormous scale of the violence in some parts of the country where the cartels have fought each other and also ravaged the civilian population in the process," said Andrew Selee, director of the Mexico Institute, a Washington-based think tank.

The widespread corruption among Mexico's police, particularly in small local forces, complicates identifications. As a result, many people with missing relatives don't approach authorities out of fear of being targeted should the officers be in collusion with criminals.

Hernandez said state investigators once told her they were afraid to look into the disappearance of her son, Jesus Everardo Lara Hernandez, because it was a "tough situation."

"They told me to understand them because they, too, had families." Hernandez said.

Hernandez, who has three other children, ages 7 to 14, said she was petrified when her son was taken, but her drive to find him was stronger and she began her own investigation and talked to her son's colleagues.

"It was very difficult because I stopped paying attention to my little ones to be able to look for him," she said. "It has been a horrible five years, but the hope of finding him keeps me strong."

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