Berta Garcia feels exhausted and ill after eight years of searching for her son Manuel -- one of the more than 100,000 people missing in violence-wracked Mexico.

With little hope of finding Manuel alive, she is in no mood to listen to candidates' security proposals ahead of presidential and legislative elections coming up on June 2.

Politicians are full of promises "but when the time comes they don't fulfill them," said Garcia, whose son disappeared in 2016 in the northern border state of Chihuahua.

Spiraling criminal violence has seen more than 450,000 people murdered since the government of then president Felipe Calderon launched a controversial military offensive against drug cartels in 2006.

Many Mexicans see insecurity as the most urgent challenge for the next government, according to surveys.

- What's Lopez Obrador's legacy? -

Outgoing President Andres Manuel Lopez Obrador has prioritized addressing the root causes of crime such as poverty and inequality -- a policy that the left-wing populist calls "hugs not bullets."

Despite his efforts, Mexico's homicide rate remains above 23 per 100,000 inhabitants, higher than the Latin American average, according to the InSight Crime think tank.

Powerful cartels control swathes of Mexico and are involved not just in drug trafficking but other crimes including people smuggling, extortion and fuel theft.

Criminals "are realizing that it's possible for them to grow more because there's no strategy to stop it," Falko Ernst, an analyst at the International Crisis Group think tank, told AFP.

Guadalupe Correa-Cabrera, a professor at George Mason University in the United States, described the security situation as "a very serious problem that is not going to be solved by providing resources for the youth."

- What are candidates proposing? -

Ruling-party candidate Claudia Sheinbaum -- who appears on course to become Mexico's first woman president -- wants to continue Lopez Obrador's strategy of tackling crime at its roots.

"Instead of declaring war (on drug cartels), we build peace," she said.

The former Mexico City mayor has pledged to strengthen the National Guard as well as intelligence agencies, and to improve coordination with police and prosecutors.

Opposition hopeful Xochitl Galvez has put insecurity at the heart of her campaign, saying: "Hugs for criminals are over."

She has vowed to capture most-wanted criminals, recruit more police, and ensure that they receive an adequate salary in a country where corruption is considered rife among poorly paid security personnel.

Galvez has pledged to double the size of the National Guard, withdraw soldiers from civilian projects to focus on fighting criminal groups, and to build a new maximum security prison.

- What do experts say? -

For justice to be served, judges, police, prosecutors and intelligence agencies must coordinate better -- something that Sheinbaum made progress on as Mexico City mayor from 2018-2023, according to experts.

The challenge is to do so across the country of 129 million people, which would require considerable resources to repair a "broken justice chain," said Carlos Rodriguez, an independent security and intelligence consultant.

A major issue is corruption within the criminal justice system, experts say.

"If we don't fight corruption and impunity, things are not going to be solved," Correa-Cabrera said at a roundtable hosted by the Wilson Center.

Ernst thinks the issue could be tackled with the creation of enclaves where uncorrupted state actors could work and focus resources on Mexico's most violent regions.

- What would a Trump return mean? -

Mexico is already under strong pressure from US President Joe Biden's administration to curb trafficking in illicit fentanyl, a synthetic opioid that is considered responsible for tens of thousands of overdose deaths each year.

With the possibility of Donald Trump returning to the White House if he wins the US election in November, experts say even stronger pressure on drug trafficking and other issues is a real possibility.

"Mexico has to have a Plan B ready to comprehensively rethink the bilateral relationship in light of this scenario," said Arturo Sarukhan, a former Mexican ambassador to the United States.

Correa-Cabrera sees a Trump comeback as a potential "game changer" in Mexican-US relations.

"If he gets elected there's going to be more pressure for 'mano dura' (tough) policies," she said, while noting that Trump previously had an "extremely stable" relationship with Lopez Obrador.