Four Americans were kidnapped shortly after crossing into Mexico earlier this month. Two survived the violent ordeal, while two members of the group died.
Here's everything we know:
The four Americans -- Eric James Williams, Zindell Brown and cousins Latavia "Tay" McGee and Shaeed Woodard -- drove the morning of March 3 into Matamoros, Mexico, which is in the northeastern state of Tamaulipas just south of Brownsville, Texas.
"Shortly after crossing into Mexico, unidentified gunmen fired upon the passengers in the vehicle," and then put the four Americans in another car and fled, the U.S. Embassy in Mexico City said.
MORE: 4 US citizens kidnapped in Mexico identifiedIrving Barrios, the attorney general of Tamaulipas, said the Americans were not directly targeted and it appears "it was a misunderstanding."
Mexican investigators think the kidnappers may have wrongly believed the Americans were rival human traffickers, a source close to the investigation told ABC News.
For the first time, the Attorney General's Office of Tamaulipas also said on March 9 that a Mexican woman died in the incident. Arely Pablo, 33, died after being hit by a stray bullet during the kidnapping.
Williams and McGee survived the kidnapping. They were found the morning of March 7 in a wooden house in the Lagunona area, outside of Matamoros, Mexican officials said.
One of the deceased was also found inside the house, and the second was found outside the house, a source close to the investigation told ABC News.
The two Americans found dead had blankets or sheets on top of them, a source close to the investigation told ABC News. One of the dead was wearing a surgical robe when he was found, the source said.
The Mexicans tried to seek medical attention for the Americans who were injured in the kidnapping, the Attorney General's Office of Tamaulipas said in a statement on March 9. They were taken in an ambulance to a clinic, according to officials.
During the days they were held, the Americans were transferred to various places, including a clinic, in order to create confusion and avoid rescue efforts, said the governor of Tamaulipas, Américo Villarreal.
McGee is a mother of five who traveled from South Carolina to Mexico for a cosmetic medical procedure, according to her family.
Her mother, Barbara Burgess, told ABC News she spoke to her daughter on Tuesday. She said McGee had no major injuries.
Michele Williams, wife of survivor Eric Williams, said the FBI told her that her husband had been shot twice in one leg and once in the other.
He has undergone surgery in a Texas hospital, she said.
Brown, who was among the two killed, was on the trip to Mexico to support his friend, McGee, for her surgery, according to Brown's sister, Zalayna Brown Grant.
"Zindell was a loving son, brother, uncle and friend," Grant wrote on a GoFundMe page. "Our family waited for any news about my brother's return, but he won't be coming home alive."
Woodard, who was also killed, was McGee's cousin, according to McGee's mother.
The bodies of the two Americans killed were repatriated to the U.S. on March 9.
A fifth person who was traveling with the group, Cheryl Orange, did not cross the border into Mexico and remained in Brownsville, according to a police report from the Brownsville Police Department.
Orange did not cross into Mexico because "she did not have her ID with her" and contacted police on March 4, the day after the kidnapping, when she could not get in touch with them, the police report said.
Five alleged members of a powerful Mexican cartel were charged with aggravated kidnapping and murder on March 10 in connection to the kidnapping.
The Attorney General's Office of Tamaulipas announced the charges a day after the Gulf Cartel allegedly took responsibility for the kidnapping. The five men were found tied up near a pickup truck and a handwritten note was found placed on the windshield of the truck, whose author or authors say they belong to the Gulf Cartel, the dominant organized crime group in this part of Mexico. Neither ABC News nor U.S. officials have been able to independently verify the authenticity of the note.
The alleged cartel members have been indicted in connection with the kidnapping, the Tamaulipas attorney general announced Monday.
A 24-year-old suspect arrested in connection with the incident was formally indicted on an aggravated kidnapping charge, the Attorney General's Office of Tamaulipas said on March 10. The man was allegedly acting as a lookout when authorities finally located the four missing Americans.
The office also announced a homicide charge in the killing of Pablo, the bystander.
The FBI said it's working with "federal and international partners to determine the facts of what happened and to hold those responsible for this horrific and violent attack accountable for their crimes."
Following the recovery of the victims, National Security Council spokesperson John Kirby said, "Attacks on U.S. citizens are unacceptable, no matter where, under what circumstances they occur. We're going to work closely with the Mexican government to ensure that justice is done in this case."
President Joe Biden has "been kept updated" on the situation, White House press secretary Karine Jean-Pierre said on March 7.
The FBI urges anyone with information to call its San Antonio office at 210-225-6741 or submit information on its website.
ABC News' Miles Cohen, Ellie Kaufman, Matt Rivers, Anne Laurent, Shannon Crawford, Dan Carranza and Luke Barr contributed to this report.