When 43 students
went missing in a controversial case that drew global attention to Mexico's struggles with violence and corruption
, he led search parties trying to find them.
And when more families in his state came forward reporting that their loved ones had disappeared, he organized searches for them, too.
Saturday night, investigators in Mexico's Guerrero state say Miguel Ángel Jiménez Blanco was found dead inside a taxi he owned, with two gunshot wounds. Authorities haven't said whether there are any suspects in the slaying.
Jiménez was a vocal leader of citizen self-defense groups in Guerrero and a sharp critic of local officials, who he accused of hiding evidence tied to the students' disappearance.
Last week, Jiménez told CNNMexico that more than 100 bodies had been found in hidden graves in the area since October, decrying what he called a worsening security situation.
He said he'd recently started driving a taxi to make ends meet. After years of working to clean up the streets, he said he was once again worried about safety.
"We left it clean and now again there are bad people here, but we have to do something, because I cannot leave this to my children," he told CNNMexico. "If something happens to one of my children I will never forgive myself."
Leader of self-defense groups
As violence surged in Guerrero in 2013, Jiménez was among a number of local leaders who formed so-called community self-defense groups
that aimed to take over security in areas where residents had long complained that the government wasn't doing enough to protect them.
In the town of Xaltianguis, located about 40 minutes from the violence-plagued Pacific resort city of Acapulco
, Jiménez led a group of more than 100 women who took up weapons and began patrolling the streets.
A year later, he formed another group of community police in the same area, according to CNNMexico.
When 43 students disappeared after a night of violence in the town of Iguala, Jiménez and his group joined the search.
They also formed a new group known as "The other disappeared," looking into the cases of people who'd been reported missing since 2008, CNNMexico reported.
Parents of missing students protest
More than 10 months after 43 students went missing during a night of violence in Iguala, Mexico
, remains of just one of them have been positively identified
. Authorities have said the remains of all of the students were dumped into a river, but were so badly burned that it's impossible to identify the others.
Mexico's government has officially declared them dead.
But parents of the missing students have continued protests for months. Their search for their loved ones won't stop until they get answers from the government that they can believe, Melitón Ortega, whose son is among the missing, told CNNMexico last month
"Even though politicians and authorities ask us to accept that our 43 students were killed," he said, "we will keep looking for them alive as long as what happened is not explained with irrefutable scientific proof."