"To premeditate and say he would put a bullet in my colleague's head - that certainly crosses a line that no one went to yesterday instead of him", Rep. Justin Rodriguez, D-San Antonio, said.

Witnesses said Rinaldi approached several Hispanic lawmakers and said he had called Immigration and Customs Enforcement officials on the protesters.

Hundreds of people gathered in the public gallery of the Texas Capitol on Monday to protest a new law cracking down on "sanctuary cities," sparking a heated altercation - among lawmakers, not the demonstrators.

On Monday afternoon, Rinaldi stated on Facebook that Nevarez had "threatened my life on the House floor after I called Ice on several illegal immigrants who held signs in the gallery which said "I am illegal and here to stay". "Undocumented and afraid", they chanted.

Eventually police cleared the gallery entirely, and the protesters joined almost a thousand other activists in the State House rotunda, marching through its halls and chanting slogans against the law for the next hour. On Monday, the last day of the Texas legislature's regular session, protestors filled the house gallery to oppose the controversial State Bill 4.

Rinaldi said that he was angry because the lawmakers were "bragging" about the protesters breaking House rules, which prohibit any display of support or opposition from the gallery. "We were waving, and that's when he made a decision to come by us and tell us that he called ICE", Romero said. In a statement, Rinaldi said state Rep. Poncho Nevárez, D-Eagle Pass, "threatened my life on the House floor", and that he was "pushed, jostled and someone threatened to kill me ..."

The Republican released a statement in which he accused Representative Poncho Nevarez of saying he would "get me on the way to my car" and said Ramon Romero had assaulted him while other Democrats had had to be held back by colleagues. According to Blanco, Rinaldi "came to us and said he had made a phone call to ICE [and] that he was happy that many of these people would be deported".

SB 4 requires local authorities to cooperate with federal immigration authorities and prohibits local authorities from banning law enforcement officers from asking about immigration status. "That kind of threatening language, he needs to be called out and held accountable for".

It was Republican Rep. Matt Rinaldi who said he'd call immigration police on the protesters, but officials say they never got that call.

Mr Rinaldi and several Democrats have traded lurid accusations about what happened next.

Castro said his fears about the bill leading to racial profiling were realized through Rinaldi's actions. It would also allow for local officers to be penalized if they intentionally push back against federal requests to detain suspected illegal immigrants.