NAVAJO — Sister Marguerite Bartz had worried just weeks ago about crime in the community after someone broke into the St. Berard Mission Church and stole bingo money.

Then she herself fell victim to a horrible crime.

The beloved nun was murdered in her residence on church property, a killing that has rattled this impoverished town on the Navajo Indian Reservation and left parishioners in mourning.

"She was like a mom to me," said resident Arlene Deche. "It was so sad to hear what happened to her."

When Bartz, 64, failed to show up as scheduled for Sunday Mass in the neighboring community of Sawmill, a person who hasn't been identified was sent to check on her welfare.

The church property sits along a highway against a scenic backdrop of red rock cliffs near the New Mexico-Arizona border. Her death turned tragedy loose on a town long beset by economic hard times, with its boarded-up, graffiti-scarred houses and weed-strewn playground.

Parishioners sobbed and hugged in the church parking lot as Bartz's roommate, who would only identify herself as Sister Magdalena, returned Wednesday to the residence they shared.

Sister Magdalena was in New Jersey when the crime happened. She said she now plans to move to the larger town of Fort Defiance, Ariz., 15 miles south of Navajo.

"She did a lot of counseling with people that were having difficulties," Magdalena said. "It's hard for anybody to understand the depth of what she did. She wanted so much to empower the people. She wanted them to know how good they were."

The FBI is investigating Bartz's death. Spokesman Darrin Jones said Wednesday that a quick arrest is not likely but investigators received preliminary autopsy results that showed Bartz "sustained a substantial amount of trauma, likely as a result of a violent confrontation" with her killer or killers.

Jones said agents are withholding the specific cause of death while the investigation continues. However, he said there was no evidence to suggest Bartz was sexually assaulted or that she was targeted because she was a nun or for religious reasons.

A small sport-utility vehicle Bartz had used was transported to Albuquerque for processing by investigators. It arrived with a sheet draped over the driver's side, covering the window.

The FBI has declined to provide any motive for Bartz's murder or to say how she was killed, but said the murder apparently happened Halloween night or early Sunday. Autopsy results were pending.

Parishioners Deche and Mary Petersen said Bartz had served Navajo and the surrounding communities for a decade and had success converting people through her work.

When they talked about Bartz, they spoke of her in the present tense.

"She makes me and my family feel really safe," Deche said.

Deche and others said Bartz prayed with them in their homes and traveled to the homes of elders on the remote reservation. She offered advice on raising children, ran bingo and religious education classes, played guitar and learned the Navajo language to sing Navajo songs.

She had a big smile.

"She seemed to be a person who got really close to people. She had a huge impact on people's lives and really reached out to families in need among the people she served," said Lee Lamb, spokesman for the Diocese of Gallup.

Mary Petersen of Navajo said she was worried about two women living alone with no dogs or a man to protect them.

Rough economic times started here more than two decades ago with the closure of a sawmill that had employed up to 400 people. While many stayed in Navajo — the population is roughly 1,500 residents — jobs are scarce and many villagers are poor.

The streets have potholes, and abandoned houses are covered with black graffiti.

About five years ago, the local recreation hall shut down, said Raymond Howard of Navajo. A playground and basketball court are overgrown with weeds. Residents worry there's not enough to keep teenagers busy.

Petersen worried that other religious workers might stay away from the town, but Deche said she takes comfort in knowing that Bartz's spirit will look over the little church.

"In spirit, she's here. She's not going to leave us. She's not going to abandon us. She's going to lead us on," Deche said.

A Facebook page set up for St. Catherine Indian School alumni was filled with accolades and sadness for Bartz from her former religious education students and colleagues now scattered across the country. Many students remember Bartz for making them care about social justice issues such as hunger. One remembers Bartz for giving her a 12-string guitar her senior year. One posted a picture of Bartz holding the student's baby.

Teresa Alarid Mowry, a Santa Fe native who attended St. Kate's from 1986-1990 and now lives in Phoenix, called her "an awesome woman. Even when you posed questions to her that maybe didn't follow Catholicism, she didn't judge you. She would just explain things and give you a different perspective."

"It's just so sad the way she died," Mowry said.

Alumnus Milton Bluehouse Jr., who set up the Facebook page, remembered Bartz as warm, encouraging and positive, but tough. "She was very insistent that we take notes and that those notes be thorough. She warned us this would be our primary learning tool when we went to college," said Bluehouse, now an attorney and the tribal liaison for the New Mexico Environment Department in Santa Fe.

Bluehouse said he wasn't one of her better students, but she was unfailingly patient with him. "She had a gift and talent for reaching out to students," said Bluehouse, who had Bartz as a teacher from 1987 to 1990.

He remembers in particular an annual event Bartz organized to raise awareness among the students of world hunger. Each student drew a number. "Based on the number they drew, a few would get a steak dinner, some would get a little less and the rest of us would get rice and water," Bluehouse recalled. "The lesson she imparted was very powerful — to be aware of those who are impoverished, of world hunger and that we care about those in our own community who are hungry."

A fellow teacher, Jennie Reasoner in Santa Fe, remembers Bartz for co-sponsoring a chapter of Amnesty International at St. Kate's and as a fellow breast cancer survivor. "She was very calm and kind. Because of her, I went to classes and became a Catholic because of her outrageous sense of justice and peace," said Reasoner, who taught with Bartz at the school from 1993 until it closed in 1998. "I am devastated by this. To me, for someone who spent her whole life working for peace and justice to die that way is just a bizarre thing to happen."

Bluehouse, who is Navajo, said Bartz's murder raises an ugly reality, "that crime in Indian Country is prevalent. A U.S. Department of Justice report (2000) found crime in Indian Country (on reservations) is twice as high as in other parts of the country."

New Mexican reporter Staci Matlock contributed to this story.