On 1 May 2015, the Jalisco New Generation Cartel (CJNG) carried out a series of attacks in Jalisco, Mexico, and four adjacent states to prevent the capture of Nemesio Oseguera Cervantes (alias "El Mencho"), their suspected leader. The operation began early that morning in Villa Purificación, where four Mexican Air Force and Federal Police (PF) helicopters spotted a CJNG convoy protecting El Mencho. As one of the helicopters flew over the convoy, the CJNG members shot it down using rocket-propelled grenade (RPG) launchers. Nine law enforcement officers died as a result of the attack, and multiple others were wounded. This was the first incident in the Mexican drug war in which organized crime groups shot down an aircraft.

As the government extended its crackdown on the CJNG, it issued its highest security alert level and coordinated municipal, state, and federal security forces. The CJNG responded to the offensive by hijacking 39 buses, trucks, and cars throughout western Mexico, setting them on fire, and using them to block roads and highways in multiple locations. They also burned several gas stations, banks, and businesses. Most of the attacks took place in Guadalajara, Jalisco's capital and the second-largest urban area in Mexico. According to the government, the scale and level of coordination by the CJNG in this attack had not been displayed by other crime groups in Mexico.

The attacks garnered international headlines and reactions from the highest levels of the Mexican government, including President Enrique Peña Nieto, who promised the dismantling of the CJNG's leadership structure. Mexico's National Security Commission placed significant attention on El Mencho, and publicly announced that they were making his arrest a priority. Over the course of a year, violence and homicides increased in Jalisco. However, as the government shifted its attention in 2016 to re-apprehend Joaquín "El Chapo" Guzmán, once Mexico's most-wanted drug lord, the CJNG readjusted its strategy and toned down its violent methods.

Background and possible motives According to the Mexican government, the attacks were one of the most brazen moves by organized crime against Mexican security forces in the ongoing Mexican drug war (2006–present). They were also unique in that a relatively new criminal group in Mexico like the CJNG was willing to confront the government head on. Though organized crime groups in Mexico had used rocket launchers against security forces in the past, it was the first time that one had shot down a military aircraft. This showed the Mexican government that the CJNG had the manpower and operational capacity to respond to government crackdowns.

The CJNG's influence in Mexico's criminal landscape had grown significantly since 2009–2010. The group was formed as a splinter organization of the Milenio and Sinaloa Cartels after several of their leaders were arrested or killed. Their international drug trafficking operations, specifically for heroin and methamphetamine, increased the group's financial power and capacity. Their market share growth in Mexican territory was also correlated with the arrest and deaths of the leaders of rival criminal groups like the Knights Templar Cartel and Los Zetas. The CJNG's stronghold, Jalisco, gave the group a strategic advantage since Jalisco ranks high in industrial output and gross domestic product (GDP).

The attack was covered in international media, prompting reactions at the highest levels of the Mexican government. President Enrique Peña Nieto told the public that day through his Twitter account that the CJNG would be dismantled by the government. Mexico's security commissioner Monte Alejandro Rubido García (es) told reporters in an interview after the helicopter attack that the government would spend significant resources to capture Nemesio Oseguera Cervantes (alias "El Mencho"), the top leader of the CJNG. The government's urgency to confront the CJNG had intensified the month before, when the CJNG ambushed and killed 15 policemen in Jalisco. The same day the attacks occurred, the government inaugurated Operation Jalisco, a military-led campaign to combat organized crime groups in Jalisco and capture their leaders. The new security operation was made up of the Army, the PF, the Attorney General's Office (PGR), and the Center for Research and National Security (CISEN), Mexico's national intelligence agency. The main target of the operation was the CJNG. Around 10,000 new troops and 300 armored vehicles were dispatched to the state for Operation Jalisco on 10 and 11 May.

The helicopter attack and the roadblocks were a response by the CJNG to the attempted capture of El Mencho. The government stated that the violence in Jalisco was a reaction to Operation Jalisco. According to sources from the PF, prior to the helicopter attack, El Mencho was spotted in Tonaya, Jalisco, which prompted a law enforcement offensive to apprehend him. His gunmen defended him from the PF and he was able to escape. The helicopter that was shot down was equipped with parachutes that were intended to be used by the officers on board. They were planning to jump off and continue their operation on foot with the goal of capturing El Mencho. Unconfirmed federal and state sources said that someone within law enforcement notified the CJNG of the surprise operation. They said the government confirmed this through wiretapping. The sources stated that the CJNG had detected unusual law enforcement activity in the area where El Mencho was hiding, but they did not have clear information on the operative against him until it was leaked by an insider. When the roadblocks occurred, rumors circulated that El Mencho was arrested by security forces. Law enforcement confirmed that they were close to capturing El Mencho, but did not confirm him among the detainees arrested that day. The government considers El Mencho the main suspect and mastermind of the 1 May attacks.

Helicopter attack

Before dawn at around 6:30 a.m. on 1 May 2015, an armed convoy from the CJNG made their way from Casimiro Castillo to Villa Purificación via dirt roads. The vehicles drove with their headlights off to avoid detection by the Mexican Air Force and the Federal Police (PF), who were doing air surveillance of the area in four helicopters. One of the vehicles was equipped with rocket-propelled grenade (RPG) launchers. As the helicopters flew over the convoy, the CJNG units opened fire. One of the helicopters, a Cougar EC725 carrying eighteen passengers, was hit on its tail with a Russian-made RPG-27 rocket launcher. Once hit, the helicopter spun several times in the air as it tried to maneuver its way back into trajectory. It then fell at a distance from where it was struck and exploded. The assailants fired six rockets at the helicopter and hit it twice; the gunmen tried shooting down another helicopter, but missed. The CJNG gunmen then attempted to execute any remaining living passengers. However, military reinforcements in the air prevented the gunmen from getting close to the collision scene and forced them to retreat. Nine passengers were killed as a result of the airstrike: eight from the Mexican Army and one from the PF. Some of the soldiers killed were part of the Cuerpo de Fuerzas Especiales, the elite special forces unit of the Army. The other passengers were taken to the Regional Military Hospitals in Guadalajara to receive medical attention. Their health conditions were not made public.

The day of the attack, the Mexican government confirmed that three military men were killed and three Army soldiers were missing, while the remaining twelve passengers (ten from the Army and two from the PF) were recorded as wounded. During the first 24 hours, their search was contained in a radius, but investigators widened the search area when the missing men were not found. On 4 May, the government confirmed that it had located the victims of the attack. They had to identify their corpses by conducting DNA tests as the bodies has been torn into pieces from the helicopter's explosion. This increased the death toll to six. On 6 May, the seventh passenger from the Army died of cardiac arrest as a result of the wounds he suffered from the helicopter's fall. The following day, one of the PF passengers died from his wounds. On 10 May, the ninth and final victim of the attack, a soldier from the Army, died at a hospital. Authorities confirmed that four other passengers had been discharged from the hospital after treatment. Five more remained in the hospital receiving medical attention.

Following the helicopter attack, the PF and military personnel cordoned the area and conducted a thorough search of the premises. They initially discovered four abandoned vehicles that they suspected were owned by the perpetrators. In the vehicles, investigators discovered military uniforms with the insignia "CJNG Special Forces High Command" with five embedded stars. No immediate arrests were made. The Army seized 15 assault rifles, 6 handguns, 2 RPG launchers, 2 LAW rocket launchers, 10 rocket launcher missiles, 5 hand grenades, 92 magazines for multiple weapons, and 3,800 cartridges of different weapon calibers. Possession of several of the above weapons was illegal under Mexican law. Authorities also seized radio communication equipment, several bullet-proof vests, and nine vehicles. One of the vehicles was equipped with tools to carry a RPG launcher. Investigators handed these items over to the SEIDO, Mexico's anti-organized crime investigatory agency. At the helicopter collision scene, several Army soldiers made a cross with wires and tied it to a tree close to where their comrades died. The cross had the logo of the special forces unit.

The smoke from the helicopter's crash lasted a few hours, and several of the helicopter's pieces scattered as far as from each other. About 24 hours after the crash, the Army reached the crash site and cordoned off the area to allow investigators to collect forensic evidence. Soldiers established checkpoints around Villa Purificación and searched vehicles leaving and entering the town. Other Army units patrolled the streets of the town and nearby highways in search of the suspects. Besides Villa Purificación, which had the largest military presence, there were also significant numbers of soldiers in Autlán and Unión de Tula.

Roadblocks and arsons

As the government deployed throughout Jalisco to crack down on the CJNG's offensive, violence erupted in 25 of its municipalities and in four surrounding states: Colima, Nayarit, Michoacán, and Guanajuato. In these areas, the CJNG hijacked 39 vehicles and established roadblocks using cars, trucks, and transportation buses. Thirty-six of the 39 hijacked vehicles were set on fire by the CJNG. According to eyewitnesses, the CJNG obtained the vehicles by pointing their weapons at drivers on the road and forcing them to a complete stop. They would then hijack the vehicles, spray them with gasoline on the inside, and set them on fire. Setting up roadblocks is a common tactic of the CJNG and other organized crime groups in Mexico; the CJNG had used roadblocks on a large scale at least three times since 2012 in an apparent attempt to create confusion after strategic arrests. Their purpose is to halt the mobility of security forces on the road and prevent them from making arrests. However, the attacks of 1 May surpassed the previous attacks in terms of magnitude and coordination. According to reports from the National Security Commission (CNS) (es), approximately 250 CJNG members participated in the attacks in an organized way; an unprecedented level of coordination. In addition to burning vehicles and setting up numerous blockades, the CJNG also burned several banks, gas stations, and businesses across western Mexico.