Matamoros is located on the south bank of the Rio Grande, directly across the border from Brownsville, Tex. The distance of 5 km between the two cities can be covered in about 17 minutes, according to Google Maps.

The FBI, which is working with Mexican law enforcement to investigate the kidnapping, is offering a $50,000 reward as authorities seek the arrest of the gunmen and the return of the victims.

Here’s what we know about Matamoros and the reasons people cross the US-Mexico border, including for health care.

What is Matamoros known for?

Every day, tens of thousands of people walk or drive across the bridge from Brownsville, Tex., to Matamoros, home to 580,000 people, for doctor appointments, trade, or everyday activities such as lunch. The shimmering green river Rio Grande meanders between the two sister cities.

Officially known as “Heroica Matamoros,” the city is located in the northeastern state of Tamaulipas, one of the most crime-ridden states in Mexico and one of six Mexican states that the State Department advises Americans not to travel to, citing the risk of crime and kidnapping.

“Criminal groups target public and private passenger buses, as well as private cars traveling through Tamaulipas, often taking passengers and demanding ransoms,” the department’s latest travel advisory said.

Tamaulipas is known for its long history of crime and lawlessness, being a main route for migrants en route to the United States, as well as for the vibrant and integrated border life shared by Mexicans and Americans on both sides of the border.

Over the past decade, Tamaulipas has become a symbol of Mexico drug-related violence and home to some of the worst human atrocities in the country, where criminal groups and drug gangs routinely fight territorial wars, terrorize communities and run kidnapping rackets.

Most recently, the city became known for its squalid makeshift tent camps where thousands of asylum seekers were made to wait as they pleaded their case under former President Donald Trump’s “Stay in Mexico” program.

In 2010 and 2011, a series of migrant killings in the town of San Fernando, about 140 kilometers south of Matamoros, shocked the country and the world. In 2010, authorities discovered the bodies of 72 migrants from Central America who had been murdered by the Zetas, a ruthless group that broke away from the Gulf drug cartel in the mid-2000s.

In 2011, gunmen ripped at least 193 people—some of them Central American migrants—from buses, clubbed them to death, and dumped their bodies in 47 clandestine graves. The two cases of mass killings of civilians on remote farms 90 minutes south of Texas marked a new level of barbarity in Mexico’s US-backed drug war.

Matamoros was not spared from this wave of violence. In 2011, 18 members of a family were taken from three homes in the city on the morning of July 9. While the women and children were released days later, despite several ransom payments, the men were never returned.

Although the city is currently under the control of the Gulf Cartel, Mexican authorities have made significant strides in improving security in recent years.

According to official data, the number of kidnappings and homicides, both locally and statewide, has dropped significantly in recent years. Currently, there are far fewer high-profile attacks such as Friday’s kidnappings and residents enjoy a relative peace.

Why do Americans cross the border for health care?

Pharmacies, dentists and optometrists appear almost as soon as you cross the border into northern Mexico. Numbers are hard to come by, but Americans regularly cross the border for health care, including cosmetic procedures, experts say.

One of the most common health reasons for Americans to cross the border is a visit to the dentist, according to academics studying the US-Mexico border.

“It’s a common phenomenon to travel to Reynosa or Matamoros for medications or medical procedures, and especially to see dentists because it’s cheaper than in Texas,” said Nestor Rodriguez, a professor of sociology at the University of Texas at Austin. “Some Mexican-Americans may feel more comfortable with Mexican doctors than with American ones.”

Prescription drugs are much cheaper in Mexico, says Kathleen Staud, a professor emeritus of political science at the University of Texas at El Paso.

For people who can’t afford medical insurance — Texas is one of the few states that have declined to expand Medicaid — health care in Mexico is an affordable option, Staud said.

Mexican pharmacies offer some advantages over those in the United States, Staud said. These include an on-site doctor who can provide low-cost medical intervention, in Spanish. There is a caveat that people traveling for medicine or care should allow time to wait in lines to cross the border.

Another advantage of Mexican pharmacies is that they offer many over-the-counter prescription drugs; that means patients can skip the waiting time and expense of a doctor’s appointment.

“The pharmacy business is booming on a frontier,” said Ricardo Ainslie, a professor of frontier culture and history at the University of Texas at Austin. “Matamoros is a major health destination, and so are towns and cities 80 kilometers west of Matamoros.”

Drugs for high blood pressure, diabetes and antibiotics are among the drugs Americans look for across the border, said Jose M. Villarreal, a professor of Chicano Latino studies at the University of Texas at Rio Grande Valley.

Others may also be looking for pain relievers like Oxycotin, Ainslie said. “People with addiction problems, who do not have a prescription or do not want to be tracked regarding their consumption, are allowed to travel to Matamoros,” he said.

Some people also travel to Mexico for surgical procedures. Ainslie said Northern Mexico has several reputable medical schools that people can travel to “to access qualified health care at a fraction of the cost of U.S. health care or surgery, despite being completely out of pocket.”

What are other reasons why people in border towns regularly move between the US and Mexico?

People who live in border towns like Brownsville, Texas or Matamoros are often binational and have been traveling for generations to see family or friends, or for work and school, according to frontier studies experts.

“There are people who regularly travel from cities in Texas to Reynosa or Matamoros, or other cities in between, to meet with family,” Rodriguez said. “There are so many families separated by the border.”

People living on the US side may also cross the border for more “coincidental reasons,” he said. Sometimes Rodriguez’s students cross the border for a good meal on the Mexican side.

Similarly, Amelie Ramirez, the director of the Institute of Health Promotion Research in San Antonio, said Hispanics often cross the border into Texas to buy groceries.

“Since cartel violence has increased in these areas, I suspect the percentage of white Americans traveling to Mexico has dropped due to security fears,” Ainslie said. “But it still exists, and people regularly travel to Matamoros for all sorts of reasons.”

At least 948,895 people entered the United States through the Brownsville border in January 2023, according to the Bureau of Transportation Statistics; in January 2000 this number was at least 1,809,300.

Kevin Sieff and Leo Sands contributed to this report.