Thursday afternoon, the two sides presented what are called mini-opening statements to potential jurors.
Such three-minute statements during jury selection are new to Colorado. The Colorado Supreme Court's Jury Reform Committee approved the use of them last year.
The prosecution went first saying Andrade, 32, intentionally and deliberately murdered Angie Zapata, 18, on July 16, 2008.
Zapata was born male, but was living as a woman.
Weld County Deputy District Attorney Brandi Nieto said the two had met online.
After meeting in Thornton, Nieto said Zapata took Andrade back to her Greeley apartment.
It was there, she said, Andrade beat Zapata to death with a fire extinguisher.
"You're also going to learn from the evidence that there's absolutely no evidence of any sexual activity occurring either on or around the time this murder was committed," Nieto said.
Andrade's defense attorney, Annette Kundelius, followed saying Andrade did kill Zapata, but argued the murder was a crime of passion and doesn't rise to the level of first degree murder or a bias motivated crime.
"When [Andrade] learned Angie was in fact Justin and was a male, he immediately reacted to that," she said. "He had been deceived and he reacted."
Jury selection will resume Thursday.
After a jury is seated, full opening statements will be made. The trial is expected to last through next week.
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