Mexico City, May 18 (teleSUR-RHC)-- Mexican political candidate Hector Lopez Cruz from the Institutional Revolutionary Party (PRI) was killed in a drive-by shooting on Thursday, marking the latest assassination against a political candidate ahead of Mexico's June 7 mid-term elections. "Today with this cowardly murder, for the first time in recent memory, this act of violence has tainted the electoral process,” the PRI said in a written statement.

Since the beginning of 2015, more than a dozen candidates across the country have been killed, kidnapped, or threatened. "Unfortunately, what happened is not an isolated incident, we constantly hear about these types of incidents through the media; homicides and kidnappings, without any action from the local authorities,” the statement read.

Meanwhile, that same day in the nearby state of Michoacan, mayoral candidate Enrique Hernández Salcedo from the National Regeneration Movement (MORENA) party was brutally murdered after a campaign rally. Following the incident, the MORENA party issued a statement describing Hernández’s murder as a “State crime”, accusing the interim state government of failing to provide its candidates with adequate protection.

Much of the political violence is tied to organized criminal factions seeking to dictate the result of the elections by appointing their own candidates or influencing the behavior of elected officials through the use of violence.

Similar incidents occurred ahead of the 2013 local elections, when at least 20 candidates were killed or kidnapped. More than 83 million Mexicans are eligible to cast ballots July 7 to choose 500 federal legislators, nine state governors and hundreds of regional and local office holders.