CIUDAD VICTORIA, Mexico — An unidentified informant's description of armed men, people with blindfolds, and a lot of activity near a ranch helped Mexican authorities locate the remote shack where four kidnapped Americans were being held.

According to Mexican investigative documents seen by The Associated Press on Friday, authorities travelled to the rural region east of Matamoros on Tuesday morning after leaving the highway and searching for the specified location via winding dirt roads.

At last, a white pickup matching the one the Americans had been loaded into last Friday was parked outside the wooden shack, which was far from any houses or buildings and surrounded by brush. Then they started to hear someone yell, "Help!"

The documents claimed that Latavia "Tay" McGee and Eric Williams were bound inside the shack. The bodies of Shaeed Woodard and Zindell Brown, which were covered in blankets and plastic bags, were lying next to them. McGee and Williams yelled desperately in English to the authorities when they showed up.

The documents claimed that a guard who attempted to flee through a back door was quickly apprehended. Although he was sporting a tactical vest, he was not described as having a weapon.

To allow McGee to have cosmetic surgery, the four Americans travelled from Texas to Matamoros. They were fired upon in the centre of Matamoros around noon and then loaded into the pickup truck. After being unable to contact the group that crossed the border, another friend who was still in Brownsville called the police. Areli Pablo Servando, a 33-year-old Mexican woman, also perished, presumably from a stray bullet.

The Scorpions faction of the Gulf cartel wrote a letter of apology to the people of Matamoros, where the Americans were abducted, to Servando, and to the four Americans and their families. The letter was obtained by The Associated Press on Thursday through a Tamaulipas state law enforcement official.

However, the supposed apology, according to the family members of the kidnapped Americans, hasn't done much to lessen the pain of losing their loved ones.

Woodard's father claimed that when he learned that the cartel had expressed regret for the violent kidnapping that was documented on video and quickly went viral online, he was left speechless.

"I've just spent the last week trying to understand it. Simply restless, unable to eat or sleep. To have your own child violently taken away from you in that manner is just crazy. James Woodard told reporters on Thursday that his son didn't deserve to die.

Williams' cousin, who was shot in the left leg during the abduction, said that while his family is "great" to know that he is alive, they will not accept the cartel's apologies.

Jerry Wallace said to the AP on Thursday that nothing about the suffering we endured would change as a result. Wallace, 62, demanded that the governments of the United States and Mexico do more to combat cartel violence.

U.S. officials contacted President Andrés Manuel López Obrador directly over the weekend to request assistance in finding the missing Americans in Matamoros, according to U.S. Ambassador Ken Salazar, who revealed to reporters on Friday. The cartel there "must be dismantled," he said.

The letter purportedly from the cartel denounced the violence from the previous week and claimed that the gang had handed over its own members to law enforcement.

In the letter, the cartel states that it has "decided to turn over those who were directly involved and responsible in the events, who at all times acted under their own decision-making and lack of discipline," adding that these people had broken the cartel's rules, which include "respecting the life and well-being of the innocent."

The letter, which was shared with The Associated Press on the condition that they remain anonymous because they were not authorized to do so, was accompanied by a picture of five bound men lying face-down on the ground.

Five men had been discovered tied up inside one of the cars that authorities had been looking for, according to a different state security official, along with the letter. Due to their lack of authority to discuss the case, that official also spoke on the condition of anonymity.

State prosecutor for Tamaulipas Irving Barrios tweeted on Friday that five individuals connected to the violence had been detained and charged with aggravated kidnapping and homicide. Only one other person, according to him, had been detained recently.