"They handled this situation in a very unprofessional manner. These are not the standards of the United States government," Alejandro said in an interview with AFP.

Narciso Barranco, father of three Marines, was intercepted by Immigration and Customs Enforcement agents Saturday while trimming a garden at a restaurant in Santa Ana, a city south of Los Angeles.

The incident was captured by witnesses in videos that spread like wildfire on social media. From different angles, Barranco, 48, is seen running with a weed whacker in hand before several agents beat, subdue and pepper-spray him.

"It's very hard to watch," said Alejandro, 25.

Tricia McLaughlin, assistant secretary of the US Department of Homeland Security, said in a statement to AFP that Barranco tried to flee and "brandished a weed whacker directly at an officer's face," so officers took appropriate action.

McLaughlin added that they used "the minimum amount of force necessary to resolve the situation in a way that prioritized the safety of the public and our officers."

But Alejandro disputes the claims.

"The video shows (Narciso) moving the weed whacker. I think it's natural instinct because he was sprayed with something seconds before...but he never brandished it directly at an officer," he said.

"There's a guy holding his gun sideways, finger on the trigger pointing at a vehicle. I don't see how that makes sense. The minimum amount of force doesn't include restraining a man and repeatedly hitting him in the neck and face areas. I think that's the maximum amount of force short of lethal force."

- 'Swallowing orders' -

The case has sparked criticism in California, in part because Barranco's three sons are in or have been in the United States Marine Corps.

Alejandro has left the military, while two brothers are stationed at Camp Pendleton, also in Southern California.

The arrest also occurred amid a tense climate in the Democratic state, with protests against the raids, and where Trump sent thousands of National Guard troops and 700 Marines to support immigration operations among other things.

Alejandro says he knows these troops and understands that they are "swallowing orders" and doing their job.

"I do feel that some of them are suffering. Some are confused because perhaps some of their relatives are undocumented and they see all this, and I think it's hard for them."

Trump returned to the White House riding an anti-immigration wave and promising to deport millions of undocumented immigrants, whom he called "criminals" and "the worst of the worst."

However, under pressure from immigration authorities to increase daily arrests, street operations have shaken workplaces such as car washes, hardware stores and street vendors.

Activists, non-governmental organizations and families denounce the detention of people without criminal records, identified for staying or entering the United States illegally.

The case of Narciso Barranco, who emigrated from Mexico in the 1990s, follows that of the wife of another former Marine in Louisiana, who was detained in May after leaving an immigration appointment to process her legal status.

- 'There has to be a change' -

Alejandro saw his father for the first time on Tuesday at a detention center in downtown Los Angeles.

He told AFP that his father is being held in a cell with at least 70 other people, with only one toilet, very little food, and "minimal water, like once a day."

Narciso, with wounds and bruises, received medical attention Tuesday night, Alejandro said, adding that his father hasn't been able to wash and still has blood on his shirt, the same one he was wearing when he was arrested.

"There needs to be a change," Alejandro said in a calm but sad tone, referring to Trump 's immigration policy. "They're taking away workers who came here to make this country even greater.

"They came to give their children a good education and teach them to serve, to give back, and to be grateful for this country, as my brothers and I are."