Recent months have seen contrasting fortunes for police on Latin America's two key fronts in the war on drugs.
A large reward had been offered for the capture of the Mejia Munera twins
In Mexico, 1,378 drug-related killings have taken place so far this year, a rise of 50% compared with the same period in 2007. Acting chief of police Edgar Millan was among the victims.
In Colombia, authorities followed a series of successes against leading drug-traffickers by capturing one of the wanted Mejia Munera twins and shooting dead the other.
"These countries are at different stages of the timeline," an unnamed US official told the BBC.
"Mexico is wrestling with its demons right now, and those demons got fairly powerful because they were able to manifest over a couple of decades.
"Colombians recognised early on that the cartels were a threat to their national security and have been aggressively dismantling those Colombian cartels for over two decades."
So can Colombia's greater experience hint at a way forward for Mexico?
The two countries form different links in the drugs supply chain. Mexico is responsible for some poppy and cannabis production, but no coca cultivation.
However, its 2,000-mile (3,200km) border with the US has made it central in the trafficking of cocaine, the vast majority originating from Colombia. Ninety per cent of the cocaine which enters the US passes through Mexico first.
What both Colombia and Mexico have experienced are large, violent drugs cartels.
Pablo Escobar and his Medellin cartel were synonymous with violence
"In Colombia, in the late 1980s and early 1990s, the mafias got out of control and developed the capacity to challenge the state," says Alfredo Rangel, a Colombian security analyst.
"The Mexican cartels' tactics resemble those of the Medellin cartel."
The Medellin cartel's leader, Pablo Escobar, was behind crimes ranging from the 1984 assassination of Colombia's minister of justice to later terrorist attacks on major cities.
Colombian authorities managed to dismantle the Medellin cartel and its rival, the Cali cartel, by the mid-1990s. Can Mexico do likewise with its drug gangs?
According to the US official: "The first lesson is - and (Mexican) President (Felipe) Calderon and his predecessor President (Vicente) Fox got it - that there's got to be political will."
Before Mr Fox, of the National Action Party (PAN) was elected in 2000, US authorities were concerned about Mexico's lacklustre response to drug trafficking, and some members of the ruling Institutional Revolutionary Party (PRI) were alleged to have made pacts with drug traffickers.
The Colombian government was able to draw on public outrage in the early 1990s.
According to then Defence Minister Rafael Pardo: "The government showed that the traffickers weren't positive as many people thought, and that there couldn't be indifference towards them."
Public support for the government's strategy was consolidated by moves such as Escobar's killing in 1993.
The drug baron was tracked down by a specially-formed police unit, acting with US assistance. The government later bolstered its efforts by modernising intelligence institutions and offering gang members incentives to turn informants.
Mexico's disadvantage, compared with Colombia's centralised police service, is a disjointed system of local, state and federal forces.
These forces are notoriously corrupt, and President Calderon has sought to bypass them using the military.
Mexican troops have been sent to some of the most violent areas
Some 30,000 troops have been sent to various parts of the country.
This strategy is controversial.
"In Colombia the headway that has been made - such as the arrest of (top drugs boss) Diego Montoya - has a lot to do with good police work. The military is not made for fighting for organised crime," says Markus Schultze-Kraft of the think-tank International Crisis Group.
"Troops don't have the intelligence tools to know where to hit drug-trafficking organisations and there's a higher risk of human rights violations. So instead we would advise the Mexican authorities to focus on police reform."
Another central aspect of tackling drug-trafficking is controlling money-laundering. An estimated $10.2bn (Ł5.1bn) of illegal revenues entered Mexico in 2004 alone.
Colombia's own response has been stringent banking regulations and police intelligence.
When trafficker Juan Carlos Abadia was arrested in Sao Paulo last year, police soon confiscated an estimated $700m of his assets.
The shortcomings of Colombia's efforts are nonetheless apparent. Dismantled cartels have been replaced by new groups with evolved tactics.
"Many people in the Medellin cartel ended up working for the paramilitaries," says Mr Schultze-Kraft. "The modus operandi of the paramilitaries was highly violent but was not directed against the state."
Instead, the paramilitaries, who formally demobilised under a 2005 agreement, used their drugs revenues for political influence.
"One error which Colombian society committed was to underestimate the links between the mafias and political institutions," says Mr Pardo, now an opposition senator.
More than 50 members of congress are being investigated for paramilitary links.
If, as many analysts predict, Mexican cartels fragment and resort to political corruption, these judicial investigations may prove useful precedents for Mexican authorities.
Critics say troops should not be used for what is essentially police work
However, such measures seem unable to compensate for the failure to tackle the demand for, or supply of, illegal drugs.
"Mexico will continue to experience serious problems with drug trafficking as long as the drug flow from the Andean countries is not considerably reduced," argues Mr Schultze-Kraft.
According to drugs expert Francisco Thoumi, Mexico will withstand the problem better than Colombia.
"It has a much bigger economy and so drug-trafficking has less capacity to penetrate it. It's also next to, and therefore more important to, the US."
As Colombia and Mexico become more effective at targeting trafficking, the fear is that the burden may be shifted to other Latin American countries even less equipped than they were