Oscar Rosales, 51, was taken into custody by law enforcement authorities in the Mexican border city of Ciudad de Acuña on Wednesday and returned to the U.S. around noon, Val Verde County Sheriff Joe Frank Martinez told reporters.
Rosales was being processed before he was turned over to law enforcement from Houston, Martinez said.
"We are working with our law enforcement partners to begin the process of returning Rosales to Harris County," the Houston Police Department tweeted earlier.
Rosales was wanted for the capital murder of Corporal Charles Galloway, who served with the Harris County Precinct 5 constable's office.
During a news conference Monday, Harris County District Attorney Kim Ogg said the name "Oscar Rosales" might be an alias.
She promised upon apprehension, her office would ask a judge in Harris County to hold Rosales without bail.
Rosales’ common-law wife and brother also were arrested and charged with tampering with evidence, authorities said.
‘Ruthless, savage execution’
Houston police Chief Troy Finner said there’s video evidence of Rosales shooting the corporal.
"This is a murderer. This is a ruthless, savage execution," Harris County Constable Ted Heap said Monday. "Somebody like this needs to be removed from the streets and removed from the streets very quickly."
"Somebody like this needs to be removed from the streets and removed from the streets very quickly."
Authorities were offering a $60,000 reward for information.
The killing of Galloway and other law enforcement officers drew a heated response from U.S. Sen. Ted Cruz, R-Texas.
"The vicious attacks against law enforcement we’ve seen across Texas – and across our country – are unacceptable," Sen. Ted Cruz, R-Texas, told Fox News Digital. "I’m glad to see this murderer has been apprehended and the process has begun to bring him back to Texas. We need to send a clear message to anyone who would harm our men and women in uniform: we will find you, and if you’re still standing when they bring you in, you will pay the price."
"The vicious attacks against law enforcement we’ve seen across Texas – and across our country – are unacceptable."
Court documents reveal that Galloway, a 12-year veteran with Precinct 5, turned on his emergency lights just after midnight Monday to pull over a white Toyota Avalon, allegedly driven by Rosales. The vehicle continued at a slow pace before pulling over, and Galloway began notifying dispatch of the stop.
Dash camera footage shows the driver stepped out of his car with a rifle, pointed the weapon at the corporal and fired multiple shots toward him. The driver got back into his car and drove away, according to the court documents obtained by Houston's KHOU-TV. Houston police and fire units responded to the shooting scene.
Galloway, 47, was pronounced dead at the scene about 5 a.m. Court documents list his official cause of death as a single gunshot wound to the left side of his face.
Fox News' Bradford Betz contributed to this report.