EL PASO, Texas — The suspect accused of killing 22 people at an El Paso Walmart told authorities that he was targeting “Mexicans” and confessed to carrying out the shooting rampage when he surrendered to authorities, according to police.

Patrick Crusius, whom authorities have identified as the gunman who killed more than people at an El Paso, Texas, shopping area on Aug. 3. Photo provided by the FBI

Law enforcement officials responding to the scene on Saturday spotted a car stopped at an intersection not far from the Walmart, an El Paso police detective wrote in an arrest warrant affidavit obtained by The Washington Post. They then saw a man – identified as Patrick Crusius, the 21-year-old charged with capital murder in the case – get out of the car with his hands in the air, the affidavit said.

He told them, “I’m the shooter,” Det. Adrian Garcia said in the affidavit, which was filed to a judge on Sunday, the day after the shooting.

Authorities believe Crusius was the author of a statement posted online shortly before the attack that decried what it called a “Hispanic invasion of Texas.” Federal officials have called the attack – which also injured dozens of people – domestic terrorism and said they are weighing federal hate crimes charges in the case.

The El Paso rampage was one of two mass shootings to occur within a day. Just hours later, a gunman in Dayton, Ohio, killed nine people before police officers shot and killed him.

Crusius has been in jail since surrendering. Authorities say he has been cooperative and has answered their questions. Greg Allen, the El Paso police chief, said the suspected attacker seemed to be “in a state of shock and confusion” and has not shown any remorse to the investigators.

According to Garcia’s affidavit, Crusius waived his right to an attorney and agreed to speak, telling police he traveled from Allen, Texas, a suburb of Dallas, with an assault rifle and multiple magazines.

“The defendant stated once inside the store he opened fire using his AK-47 shooting multiple innocent victims,” Garcia wrote. The detective added that Crusius said his targets were “Mexicans.”

The car he emerged from on Saturday was about a half mile from the Walmart, stopped on a street that essentially divides shopping areas from residential areas.

Garcia wrote that Texas Rangers heading to the shooting saw the vehicle stopped in a left-turn lane. It was unclear where Crusius was heading, though Allen has suggested that he did not know the area well and got lost in a neighborhood upon arriving.

An attorney for Crusius did not immediately respond to a request for comment about the affidavit.

Crusius’ relatives have decried “the destruction Patrick did” and condemned the ideas described in the online statement.

“Patrick’s actions were apparently influenced and informed by people we do not know, and from ideas and beliefs that we do not accept or condone, in any way,” his family said in a statement released through an attorney. “He was raised in a family that taught love, kindness, respect, and tolerance – rejecting all forms of racism, prejudice, hatred, and violence.”

The FBI has dispatched officials from a domestic terrorism-hate crimes fusion cell to investigate the El Paso shooting. The bureau also said this week it is investigating the Dayton shooter after learning he was interested in “violent ideologies” and, separately, announced that it had opened a domestic terrorism investigation into a July 28 mass shooting at a food festival in Gilroy, California.

During the Gilroy shooting, six days before the El Paso attack, a gunman killed three people before fatally shooting himself. The FBI said it opened the domestic terrorism probe in that case after learning that the gunman had also explored “violent ideologies” and assembled a list of possible targets across the country.