A Nicaraguan and a Panamanian pleaded not guilty to bomb explosion charges.
A judge set a trial date of May 27 for accused bombmaker Porfirio Duarte-Herrera, 27, of Nicaragua and a co-defendant who has used names including Omar Rueda-Denvers and Alexander Perez.
Both men, who are illegal immigrants, pleaded not guilty through a Spanish language interpreter to charges in the explosion on May 7. Both remain jailed without bail.
Outside court, prosecutor David Stanton said the district attorney's office may seek the death penalty.
Duarte-Herrera and Rueda-Denvers, 32, are accused of killing Willebaldo Dorantes Antonio, 24, of Mexico, with a pipe bomb hidden in a plastic foam cup that exploded when Dorantes Antonio lifted it from atop his car in the parking lot behind the Luxor hotel-casino.
Police and prosecutors have said the bombing was a revenge murder over a tangle of romantic relationships involving a Guatemalan illegal immigrant who had a child with Rueda-Denvers and was dating Dorantes Antonio.
That woman, Caren Chali, 28, was with Dorantes Antonio when the bomb exploded. She escaped injury.
Stanton told Clark County District Court Judge Michael Villani that the trial was expected to be complex and should take at least two weeks.
"Logistically for the state this will be a difficult case to put on," Stanton said, citing a number of experts and witnesses from outside the United States who are expected to be called to testify.
Chali is expected to ask a Clark County District Court judge on Friday to let her out of the Clark County jail, where she has been held as a material witness since the bombing.
Duarte-Herrera faces additional charges over allegations he built and planted a bomb that exploded under a pickup truck last Halloween in the parking lot of a Las Vegas home improvement store. No one was in the truck and no one was hurt.
Is it possible for aggrieved nations to gain favorable international tribunal rulings against the US that force it to pay a price for its crimes?