Puddles of blood and bullet shells are some of the remnants of an intense gunfight on a western Mexico ranch that killed 42 criminal suspects and one police officer.
The authorities say superior training and equipment explains the one-sided death toll in one of the bloodiest battles in Mexico's nearly decade-long drug war.
But experts are raising questions about what really happened at the El Sol ranch in western Mexico on Friday, nearly a year after soldiers were accused of executing gang suspects following a similarly lopsided toll.
The gunfight with suspected henchmen of the Jalisco New Generation drug cartel occurred in a region considered a bastion of the gang, which has killed 28 police officers and soldiers since March.
The growing cartel, which downed a military helicopter earlier this month, has become one of the biggest challenges of President Enrique Pena Nieto's administration, which is fighting gangs in various parts of the country.
Authorities say the three-hour firefight erupted after federal forces launched an operation against suspects occupying the vast property in Tanhuato, Michoacan state, near the border with Jalisco.
"It was a very uneven fight. A battle where 42 die on one side and only one on the other is not a battle," said Raul Benitez Manaut, a security expert at the National Autonomous University of Mexico.
He said the gang apparently offered no resistance.
Hundreds of police and troops guarded the area on Saturday while investigators combed for evidence on the property, surrounded by corn and sugarcane fields.
Three puddles of blood were drying next to a broken part of the fence surrounding the ranch.
"My colleagues say one (suspect) fell here. He was trying to escape toward the hill," a state police officer told AFP.
Local media published pictures of bodies lying in fields next to assault rifles. Some were shirtless or without shoes.
White smoke billowed from the ranch's main house.
"We are burning trash. It was very dirty. There were clothes and rotten food," said another state police officer.
The officer said the suspects took over the ranch because it was isolated and strategically placed, with quick access to a highway and paths in the back toward neighboring villages.
An investigator said several bullet shells were picked up on Saturday. A day earlier, authorities seized 39 guns of various calibers, a rocket launcher and a number of cartridges.
- Details missing -
"A lot of details are missing. We don't know how many people participated in the police and military operation. We don't know if the helicopter (used in the operation) was armed," said former intelligence agency official Alejandro Hope.
"There are still a lot of doubts. The number of weapons seized doesn't match the number of dead and detained."
National Security commissioner Monte Alejandro Rubido said the authorities avoided more casualties "thanks to the training and equipment of federal forces that participated in the actions."
Rubido said the fight inside the 112-hectare (277-acre) ranch was complicated because the suspects fled into agricultural fields.
But he did not indicate how many security forces were involved in the operation or whether the helicopter that backed them used weapons.
Officials from Michoacan state and national human rights commissions went to the ranch to investigate.
- Cartel fightback? -
Hope said the burden of proof was on the authorities.
"They have to demonstrate that this was not another Tlatlaya," he said, referring to the municipality in central Mexico where soldiers killed 22 gang suspects in June 2014 in what officials initially described as a shootout.
Only one soldier was wounded. Prosecutors later charged three soldiers with murdering eight of the suspects after they surrendered.
But Samuel Gonzalez, a former anti-drug prosecutor, said the explanation behind the uneven death toll in Tanhuato was plausible because federal forces are well trained.
"The element of surprise was one of the factors," he said.
All eyes now are on whether the gang will react.
"There appears to be an order to destroy the cartel before it can consolidate," said Benitez Manaut, the security expert.
"A very tough reaction from the cartel cannot be ruled out."