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By Marlon Ramtahal

Mexican activist Miguel Ángel Jiménez Blanco, a leader in the search for 43 missing student teachers and others, was one of at least 15 people killed in a violent weekend in Guerrero, Mexico.

Jiménez, 45, was found dead inside a taxi he owned. He had two gunshot wounds. His body was slumped in the driver’s seat of the taxi found near the resort town of Acapulco, about an hour from where he lived.

He was key in searching for the 43 male college students who were presumed dead last year after they were taken captive on September 26, 2014. A group he formed also searched for hundreds of others of Mexico's "disappeared."

Serving as a vocal leader of a self-defense civilian group, Jiménez sought ways to promote security in his hometown by organizing search parties and finding loved ones who were lost in the battleground of drug cartel violence and corruption in the country. As a leader, he aimed to take over security in areas where residents had long complained that the government was not doing enough to protect the Mexican community.

The leader of a self-defense group to fight back against drug cartel violence in Mexico, Miguel Angel Jimenez Blanco, speaks with journalists on September 1, 2014, to denounce death threats he received, in the village of Xaltianguis, near Acapulco, Guerrero State, Mexico. Jimenez, who was leading a group searching for 43 missing students from Ayotzinapa, was killed on August 8, 2015 and his body found that night behind the wheel of his taxi on a highway connecting Acapulco to Mexico City, authorities in the southern state of Guerrero said Sunday. Jimenez had in 2013 started a self-defense group to fight back against drug cartel violence, and he led a civilian group that was trying to find the 43 students who went missing in September 2014. AFP PHOTO / Pedro Pardo/AFP/Getty ImagesPEDRO PARDO / AFP - Getty Images

“He taught us how to search and how to push and every day he would give us the energy to carry on,” said Mario Vergara, whose brother went missing.

The 43 missing students he searched for attended Raul Isidro Burgos Normal Rural School, an all-male teacher’s state institute that arose following Mexico’s revolution nearly a century ago with the goal of training its students to improve literacy and living conditions among the rural poor.

The students' disappearance in Iguala, Mexico, drew global attention, but parents of the students rejected the federal government’s version of events. Parents suggested the Mexican military might have played a role in the disappearance of the young men who were in their late teens and early twenties.

Related: Mexican Mayor Charged in Kidnapping of 43 Missing Students

Search parties looked for the students back in November 2014, after they were abducted by police and handed over to drug traffickers who allegedly killed the students, burnt their bodies, and dumped the bodies in a river in the town of Cocula, near Iguala. Only one students' remains have been identified.

More than 20,000 people are missing across the country of Mexico due to criminal gangs and violence connected to the illegal drug trade.

Guerrero, one of Mexico’s most violent states, had 1,514 homicides in 2014. This year, 943 people had been killed through June, according to federal statistics.

This story includes material from wire services.