(Greeley, Colorado) A man accused of beating an 18-year-old transgendered woman to death with a fire extinguisher “snapped” after finding out the teen was biologically male, a defense lawyer argued Thursday as the murder trial began.

But a prosecutor contended Allen Andrade knew Angie Zapata’s secret for at least 36 hours before the slaying – and killed her not in a sudden rage but because he disliked gays and transgenders.

Andrade, 32, would face a mandatory life sentence if convicted of first-degree murder and between eight and 24 years in prison if convicted of second-degree murder. Other charges against him include bias-motivated crime, which carries three more years, and habitual offender, which could mean decades more in prison.

Andrade’s attorney, Bradley Martin, said the case is about Zapata’s deception and his client’s reaction to that deception.

“This girl that he had just spent the last day with, was in fact a man, and Allen snapped,” Martin declared in opening statements.

Prosecutor Brandi Nieto told jurors that Andrade and Zapata communicated nearly 700 times via text message, cell phone and computer between July 12 and July 16 as Zapata was apparently searching for a roommate. She said Andrade did not make a snap decision but rather decided to kill Zapata after the pair spent hours in Zapata’s tiny one-bedroom apartment.

Andrade could have walked away once he learned Zapata was biologically male, Nieto said.

Martin, who repeatedly referred to Zapata as “Justin,” said the deception started with Zapata’s profile on a social networking site that said she was a straight female.

The two met July 15 and spent the day together, Martin said. Zapata’s clothing and other details in her apartment indicated she was female, the attorney said.

Andrade told investigators that Zapata performed oral sex on him but wouldn’t let him touch her, according to an arrest affidavit.

Left alone in the apartment, Andrade noticed photographs that led him to question Zapata’s gender. When he confronted her, she answered: “I am all woman,” according to the affidavit.

Nieto showed jurors partial transcripts of tape-recorded jail calls in which Andrade allegedly told his girlfriend that he “snapped” and that “gay things need to die.”

In another transcript, Andrade downplays the slaying. “It’s not like I went up to a school teacher and shot her in the head, or killed a straight law-abiding citizen,” he said in the transcript.

Martin said the jail calls were taken out of context as Andrade joked with his girlfriend about a crime he knew he didn’t commit.

Andrade was arrested July 30, nearly two weeks after Zapata’s sisters discovered her body under a blanket in her apartment. Andrade told investigators that he struck Zapata twice in the head with a fire extinguisher and thought he had “killed it” before striking her again as she struggled to get up, the arrest affidavit said.

Andrade is believed to be the first person tried for a hate crime under the sexual orientation section of Colorado’s hate crime law, according to the New York and Los Angeles-based Gay & Lesbian Alliance Against Defamation. Colorado is one of 11 states to have such designations in their laws.

Andrade has five felony convictions, according to court records.