The execution chamber of the 'death house' at the Southern Ohio Correctional Facility in Lucasville,Ohio. (CAROLINE GROUSSAIN/AFP/Getty Images)
Garza is the second man to be executed in Texas this month. Caroline Groussain/AFP/Getty Images

Texas executed Manuel Garza Jr by lethal injection on 15 April for killing a police officer, it was announced by the Texas Department of Criminal Justice. The execution is the second time a convicted police killer in Texas in less than a week, the Huffington Post reported.

Garza, who received a lethal injection of pentobarbital, was pronounced dead at 6.40pm local times at the Texas State Penitentiary at Huntsville, authorities said. During his final statement, the 34-year-old apologised to his family, friends and "especially police officers".

"I know you probably hate me," the convicted killer said. "What happened between me and Rocky happened too fast. I didn't know what happened. I wish y'all peace and love. I hope you have found God just like I have. God bless y'all. I will see you on the other side. I love you."

According to the Associated Press, Garza said, "Here it comes!" as the injection began to take effect. Graza's voice rose when he said "Goodbye" and let out a cry as he took his last breaths. He was pronounced dead 26 minutes after the lethal dose was injected.

Garza was convicted for the February 2001 killing of 37-year-old San Antonio police officer John "Rocky" Riojas. Rojas was a member of an elite SWAT unit that was investigating a string of property crimes at an apartment complex. He allegedly asked Garza for his name, causing Garza, who had a number of outstanding arrest warrants, to run off to avoid arrest.

The police officer eventually caught up to Garza, sparking a struggle. According to the Huffington Post, Garza grabbed Riojas's weapon and shot him in the head.

Garza maintained throughout the investigation and after his conviction, that the shooting was accidental, even blaming Rioja for the incident. "I truly think this was the cop's fault," he said in a statement to detectives at the time. "I don't see why he wanted to pull out his gun."

The US Supreme Court refused to review his case in November and no appeals were filed before his execution, the AP reported. Another convicted police killer, Kent Sprouse, was executed in Texas on 9 April.

According to the AP, Garza was the first inmate to be executed with a new supply of pentobarbital received by Texas Department of Criminal Justice. Drugs used in executions have been in short supply as drug manufacturers withhold their products due to pressure from death penalty opponents.