UVALDE, Texas (NBC) — The man who opened fire in a Texas elementary school Tuesday, massacring 19 children and two adults, was a loner who kept to himself and avoided any kind of conversation, according to the boyfriend of the gunman’s mother.

The shooter, identified by multiple law enforcement sources as Salvador Rolando Ramos, indiscriminately opened fire at Robb Elementary School in Uvalde, about 80 miles from San Antonio. He was killed by an off-duty agent with the U.S. Customs and Border Protection Border Patrol Tactical Unit and two law enforcement officers, law enforcement sources said.

Juan Alvarez, 62, who has been in a relationship with Ramos’ mother for about a year and lives with her, said Ramos had a tumultuous relationship with his mother, which often included fights.

Alvarez said Ramos left his mother’s home two months ago to live with his grandmother after he got into an intense argument with his mother after he disconnected the Wi-Fi.

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