Miguel Ángel García-Hernández, a house painter and father of four from Mexico who was critically injured by a sniper at a federal immigration facility in Dallas, has died, the second fatality of the shooting, according to Latino civil rights leaders representing his family.

Mr. García-Hernández, 32, was taken off life support nearly a week after he was shot four times on Wednesday, including in the neck, while shackled in the back of a government transit van, according to the League of United Latin American Citizens, an advocacy organization.

His wife, Stephany Gauffeny, who is nearing delivery of their third biological child, said in a statement released by the organization that her husband was “a good man, a loving father and the provider for our family.” He had lived in the Dallas area for around 20 years when he was picked up by U.S. Immigration and Customs Enforcement on a traffic stop.

“We had just bought our first home together, and he worked hard every single day to make sure our children had what they needed,” Ms. Gauffeny said. “His death is a senseless tragedy that has left our family shattered. I do not know how to explain to our children that their father is gone.”

She said they were raising funds to help support his family.

In interviews with The Times on Saturday, Ms. Gauffeny and her sister spoke of how Mr. García-Hernández had bought food for the homeless and recently shared his money with other detainees in federal custody. Ms. Gauffeny said he had helped raise two children from a previous relationship of hers, and they had two more children of their own, including an 8-year-old daughter with autism.