Anastasio Hernández Rojas, a Mexican immigrant construction worker and father of five, died in a San Diego hospital Monday after a brutal beating and tasering by US Border Patrol agents at the San Ysidro crossing to Tijuana left him brain dead.

The San Diego Medical Examiner’s Office Wednesday ruled the death a homicide, with the beating having resulted in a loss of oxygen to the brain and a heart attack.

The 42-year-old worker had lived in the Encanto, California, area since he was 14, his entire adult life. His children, ages four through 20 were all born in the US and are American citizens. He supported his family through work installing swimming pools.

Hernández had been detained and deported to Mexico on May 25  after reportedly being picked up by the San Diego police. He was again detained by the Border Patrol while attempting to cross back into the US to reunite with his family on Friday, May 28.

Immigration authorities rushed him through the system and were preparing to push him back across the border to waiting Mexican border agents when the incident took place.

The Border Patrol claimed that Hernández became violent and that it was necessary to club and then taser him into submission.

Witnesses, however, reported that as many as 20 agents pummeled the worker. His brother, Pedro Pablo Hernández, whose whereabouts are unknown and is presumed still in US custody, testified that he and Anastasio were seated on the ground in handcuffs when one of the agents kicked him in the chest and another kicked him in the leg. He said that Anastasio shouted at the agents to stop, but they only became more violent.

The murdered man’s wife, María Hernández, told the media, “What happened is that Anastasio wasn’t going to let them get away with it; I know him.”

Initially, the beating could not be seen from the Mexican side of the border, but a woman who was passing through the border transfer area towards Mexico informed agents of the Mexican National Immigration Institute that the US agents were “almost killing someone” on the other side.

Then, according to accounts in the Mexican press, Anastasio Hernández crawled to an area where he could be seen from Mexican territory, pursued by the US agents. With dozens of people watching, the agents kicked and used stun guns on him until he stopped screaming and no longer moved.

The US Customs and Border Protection agency issued a perfunctory statement declaring that it “regrets the loss of life and awaits the results of a complete investigation into this incident.”

Immigrant rights defenders, however, say that the brutal attack is by no means uncommon, and that Border Patrol personnel enjoy impunity in the use of violence against undocumented immigrants. They add that such investigations are generally internal, with no accountability to the public.

This latest killing provoked rage on both sides of the US-Mexico border. The Mexican government responded with its usual words of condemnation and indignation, but has taken no action outside of instructing its consulate in San Diego to aid the bereaved family.

The Mexican Conference of Bishops charged that the atmosphere for the killing had been created by the whipping up of anti-immigrant reaction, particularly with the passage of the law in Arizona ordering local police to target people on the basis of suspicion that they are in the country without documents. “They are encouraging hatred for Hispanic immigrants and the existence of a climate of violence based on the erroneous idea that their territories are being invaded and locals are being deprived of opportunities,” the conference said.

In the town of Mexicali, members of the Mexicali Civic Front briefly blocked the border in protest over the killing. The president of the group, Sergio Tamay, demanded justice for the murdered worker and said that efforts were being made to unite organizations in southern California and Baja California to defend the rights of immigrants, whatever their status.

At a press conference in San Diego on Wednesday, immigrant rights groups joined with the family of Anastasio Hernández to condemn the killing.

“I only wish that all those who suffered the same fate find justice, that there be justice for all of these deaths and for the death of Anastasio,” said Veronica Hernández, the murdered worker’s cousin. “They didn’t end just that one life, they took away life for all the members of our family.”

She continued: “With all that we have suffered, with immigration and discrimination, it is time that we rise up. It is time to say we are here and we have come only to work, not rob anybody. All we want is a better life for our children, for our parents.”

Andrea Guerrero of the American Civil Liberties Union in San Diego said that there was no possible justification for the level of violence unleashed against Anastasio Hernández, given that he was in a secure area after already being searched and processed, about to be turned over to Mexican authorities.

She said that the killing was not an isolated incident, but a manifestation of a “culture of impunity” within the Border Patrol. “If this kind of incident can happen in the full light of day in front of hundreds of people, what is happening behind closed doors?” she asked.

She expressed anger at the Obama White House for failing to ameliorate draconian US immigration statutes or improve conditions in any way for immigrant workers. “This administration made promises about change, but we have seen very little of it here in the border region,” she said.

Guerrero stressed that Anastasio Hernández had only two choices: abandon his family and his home of nearly 30 years, or risk his life by coming back across the border without papers. The idea that workers like him can “get in line” and return legally, she said, is a myth. “There are not lines for everybody, and this is a perfect example.”

Addressing the death of Anastasio Hernández at a press briefing Wednesday, US State Department spokesman Philip J. Crowley said that the brutal state killing “obviously represents the challenge of securing the border on both sides, and we are very mindful of the fact that [for] those who try to enter the United States illegally, there is a significant loss of life every year along the border as people endeavor to come here.”

A report released last month by the Washington-based establishment think tank National Foundation for American Policy found that 4,000 men, women and children have died crossing the border since 1998, when the Democratic administration of President Bill Clinton launched a crackdown on the border. This is approximately one person every day.

As a result of increased surveillance and repression along the border, the death rate has risen sharply, even as the number of people crossing into the US has fallen. The study found a 64 percent decline in the number of workers entering without documents, alongside a 59 percent increase in immigrant deaths at the border.