Police in Grapevine, Texas, had argued that an altercation erupted after Rubén García Villalpando disobeyed the officer's commands during a traffic stop after a high-speed chase. Villalpando's family argued that Officer Robert Clark had no good reason to open fire.

The case was one of three U.S. police shootings of Mexican nationals that drew sharp criticism from Mexico's Foreign Ministry and a call for the U.S. Justice Department to investigate.

Police said the grand jury made the right decision when it chose not to indict the officer.

"Officer Clark's actions on that night complied with Texas law concerning the use of deadly force by a law enforcement officer," Grapevine Police Chief Eddie Salame said as he narrated a video police posted on social media showing the moments leading up to the February shooting.

Villalpando's widow, Marta Romero, cried as she spoke with reporters about the case on Monday and vowed to keep fighting.

"I feel deceived, in a lot of pain, with a very deep sadness in my heart, because even though they had enough evidence to charge the officer, they did not make that decision," she said. "With the help of the lawyer we are going to move forward. We are going to search for justice."

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Attorney Domingo Garcia, who represents the family, said he's asked the Justice Department to conduct an independent investigation of the shooting. The family also plans to file a federal lawsuit against the city and the officer, he said.

"The penalty for disobeying an officer's orders is not death," he said.

Key evidence released

In the dashcam video, which authorities released to the public after the grand jury's decision on Monday, Villalpando weaves in and out of traffic as police pursue him, then eventually pulls over and holds his hands outside the car window as the officer commands.

But after Villalpando steps out of the car, his hands raised above his head, the officer shouts at him, swearing as he repeatedly orders him to stay put.

"Back up, motherf-----," Clark yells.

"Don't call me motherf------," Villalpando replies, continuing to walk forward with his hands on his head.

"Get to the back of the car!" Clark repeats.

Villalpando walks ahead, out of the view of the dashcam camera. Two gunshots are heard.

Villalpando was shot twice in the chest and later died.

What does video show?

Police say the video shows Clark following proper procedures as he interacts with Villalpando.

In an edited version of the video released by police , Salame says the officer only opened fire after telling Villalpando more than 20 times to stop walking toward him. The officer, he says, was "clearly calm and in control," only shouting to be heard over the roar of traffic and using strong language to keep Villalpando "at a safe distance."

"We've also heard suggestions that Mr. Villalpando was not a threat because at times his hands are raised, but it would only take seconds for him to change the position of his hands if he comes close enough to attack the officer," Salame says.

The video, he says, tells a different story than the one the public has been hearing about the shooting.

"No one has a definitive explanation for Mr. Villalpando's behavior on the night of February 20 but it is possible that the fact that he was legally intoxicated and was facing a second arrest for driving while intoxicated may have impacted his conduct and actions," the police chief says.

But Garcia, the attorney representing Villalpando's family, said the dashcam video shows the shooting was "totally unjustifiable."

He suggested the video could have been doctored, claiming several seconds were missing from the footage.

Even so, he said, the video shows the officer used far more force than necessary under the circumstances. He could have sprayed mace, used a police club or simply handcuffed Villalpando while he was waiting for backup, Garcia said.

"The video clearly shows that Rubén García Villalpando was shot while unarmed with his hands in the air by this officer," he said. "It once again shows that there is a double standard of justice in America. Again we see an unarmed individual shot by a police officer who gets away with murder."