Fred Martinez Jr. endured taunts and snickers from schoolmates in this remote little city on the Colorado plains, and he bore the stares and whispers of strangers on the street. But he rarely let on how much it hurt.

A lanky Navajo youth, Martinez, 16, often carried a purse. He wore eye makeup and a tissue-stuffed bra under his T-shirt, and kept his dark hair curled and styled like a woman's.

He was gay. He was transgendered. And he refused to hide it.

In school, other students would use anti-gay slurs "and say he was ugly, and why did he act like a girl when he was a boy?" recalled Robin Flores, 16, Martinez's closest friend. She described a gentle youth who masked his pain with a smile.

"I know it hurt," Flores said. "I wanted to say something back to those kids, but he'd tell me, 'No, no, it's okay -- it's just words.' "

On the night of June 16, Martinez disappeared. Five days later, his bludgeoned remains were found in a shallow canyon on the edge of town. Now the cruel words others used to define him are at the heart of a lingering question about the slaying: What was the motive?

Angry gay rights activists and Martinez's mother say they believe he was murdered because of his sexual orientation, based on alleged incriminating remarks by the suspect in the case.

They compare the killing to the 1998 murder of gay college student Matthew Shepard in Wyoming, and say it illustrates the need for an expanded hate crimes law in Colorado that would cover bias-motivated attacks on gays.

But authorities here so far have not called Martinez's slaying a bias-motivated crime, saying they lack conclusive evidence.

The suspect, Shaun Murphy, 18, of Farmington, N.M., 50 miles south of here, is a former Cortez resident with a record of violence as a juvenile. He was on probation when authorities arrested him in early July, a few weeks after the slaying, Cortez Police Chief Roy Lane said.

In a court affidavit, investigators alleged that Murphy, who apparently did not know Martinez, encountered him on a Cortez street June 16, the night Martinez was last seen alive. According to the affidavit, Murphy was later heard "bragging" to friends that he had "beat up a fag."

"It fills me with rage," said Carolyn Wagner, national vice president of Parents, Families and Friends of Lesbians and Gays. Wagner, who spent a month in Cortez comforting Martinez's mother, echoed other activists who complain officials have played down anti-gay bias as a motive because they fear the adverse publicity that befell Laramie, Wyo., after Shepard's murder.

"We want bias-motivated violence to stop," said Wagner, whose gay son survived a vicious beating in Fayetteville, Ark., five years ago. "And one of the ways to stop it is to publicly call it what it is and send a strong message that it will not be tolerated."

Martinez's mother, Pauline Mitchell, 45, a motel housekeeper, said that when her son referred to his gender identity, he occasionally used the Navajo word nadleehi, an ancient term in their culture. Long before Europeans settled on the continent, according to anthropologists, dozens of Native American tribes accepted men with feminine temperaments who adopted the dress and social roles of women and who typically preferred sexual relations with other men.

In the crueler modern world, Martinez took comfort in that history, his mother said, until "they hauled him down [in the canyon] and killed him."

Like other officials in this tidy city of 8,000 in Colorado's southwest corner, District Attorney Joseph W. Olt Jr. rejected the criticism of activists. The slaying is still under investigation, he said, and detectives are assessing all evidence, including evidence of motive.

"It may have been a hate crime or it may not have been," said Olt, who declined to comment on whether investigators have found other indications of anti-gay bias. Olt said that barring a confession in the case, the motive for the slaying may never be clearly established.

But he noted a prosecutor in a murder trial is not obligated to prove a defendant's reason for killing. Asked if he thought evidence of motive would be important to gain a guilty verdict in Murphy's case, Olt replied, "At this point, no, I don't."

He said Murphy was arrested based largely on physical and circumstantial evidence and witness statements linking him to the attack, during which Martinez was robbed of $40.

If convicted, Murphy could be sentenced to death or life in prison without parole. His lawyer declined to discuss the case, except to say her client will plead not guilty.

Lane, the Cortez police chief, complained that gay rights activists, especially those from out of town, are "trying to turn this whole thing into a big political issue."

In every annual legislative session since 1994, Colorado lawmakers have defeated bills that would have enhanced penalties for nonlethal violence motivated by anti-gay bigotry. The state's Ethnic Intimidation Act, passed in 1988, provides such penalties only when violence is motivated by victims' race, skin color, ancestry, religion or national origin.

The case of a 16-year-old youth beaten with a rock and left to die on a lonely stretch of dust because of his sexual orientation or feminine appearance likely would be a potent symbol when debate over the hate crimes issue resumes in the next legislative session, activists said.

"Yeah, of course this is political. No kidding!" said Cathy Renna, the New York-based media director of the Gay & Lesbian Alliance Against Defamation, who has met with law enforcement officials in Cortez. But, she said, "it's also very, very personal. It's about not having this kid die for absolutely no reason." .

In early July, after the affidavit containing Murphy's alleged remarks was made public, worried discussions ensued in the M&M Restaurant, which state Rep. Mark Larson owns here with his wife.

"I think there was some fear that this was going to turn into a Matthew Shepard-type incident, and that can't help any community," said Larson, who last winter became the first Republican lawmaker to co-sponsor the hate crimes bill favored by gay rights activists.

Now, talk of the slaying has faded. Most residents here agree with authorities that the motive may never be known, said Larson, who counts himself in that group.

"People may be trying to drum something out of this that's not there," he said. "I think the local law enforcement is acting in a completely appropriate way."

The youngest of Pauline Mitchell's five sons, Martinez was born in Arizona. He moved to Cortez with his mother and siblings in the early 1990s, when he was in grade school.

He was a typical boy, Mitchell said. "He used to love dressing up like a cowboy, loved playing with toy cars, loved horses." About three years ago, when he was in middle school, he changed, his mother said. "All of a sudden, he started wanting to wear makeup."

When she asked him why, "he said, 'Because I like it.' He just told me and all his brothers that that's how he was going to be. That's how he felt comfortable. And he said, 'It's up to you guys if you want to accept it.' "

In time, Mitchell said, they did.

Flores, a friend of Martinez since elementary school, also accepted his gender identity. In fact, she said, the two became closer.

"He would come over my house and I'd help him curl his hair," she recalled. "Or I'd help him put his makeup on. And we'd try on clothes together, or we'd play Monopoly, or play cards, or play video games."

Martinez's appearance prompted school officials to send him home "more times than I can remember," his mother said.

Flores said her friend, in public, rarely betrayed the pain from being singled out in school. But "he'd cry a lot with me" in private, she said. Last winter, he quit high school and enrolled in an evening program for adults seeking diplomas.

On the night of June 16, he left his mother's trailer home, saying he was headed to a local carnival. Five days later, after his mother had reported him missing to police, children playing in the shallow canyon stumbled upon his decomposed remains.

Someone had fractured Martinez's skull, most likely with a blood-stained boulder found at the scene, investigators said.

Detectives began watching Murphy's apartment in Farmington after receiving tips about his alleged comments, according to the court affidavit. According to the affidavit, Clint Sanchez, a friend of Murphy's, told authorities that he and Murphy were cruising in a car in Cortez on the night of June 16 and gave a ride to a young gay man, whom detectives allege was Martinez. After dropping the youth off at a street corner, Sanchez said, he and Murphy drove to a friend's apartment less than a block away.

Then Murphy went out alone, saying he wanted to buy marijuana, according to Sanchez, who has not been charged in the case.

"Approximately 20 minutes later," investigators wrote in the affidavit, "Shaun Murphy returned to the apartment with blood all over him and his clothes. Shaun Murphy told Clint Sanchez that he had gotten in a fight and someone was still lying in the 'Pits' " -- the area where Martinez's body was found.

The affidavit makes no mention of a motive. But filling in the blank is easy, activists said.

"The police are being very cautious, and I guess I kind of understand why they'd want to be conservative," said John Peters-Campbell, a Cortez resident and board member of the regional Gay and Lesbian Alliance for Diversity. "I don't have to be that way, though. I can say what I think. And what I'm saying is, Fred deserves better than this."

Pauline Mitchell, mother of Fred Martinez Jr., said he began wearing women's clothes at 13 "because that's how he felt comfortable."Martinez often was taunted for his appearance, a friend said. Shaun Murphy, 18, has been charged with Martinez's killing.