ALBUQUERQUE — Federal agents descended on a small community on the Navajo Indian reservation early Thursday to make an arrest in the slaying of a nun whose body was found in her home on church property.

The FBI said it arrested one person in Navajo in the death of 64-year-old Sister Marguerite Bartz, but declined to provide other details. The nun's body was discovered after she didn't show up as scheduled for Sunday Mass in a neighboring community.

"I'm sure that community hasn't been sleeping well for many nights. I think with this arrest they're going to have a better night's sleep tonight and feel a little safer in their homes,' said Lee Lamb, a spokesman for the Diocese of Gallup, which oversees the St. Berard parish in Navajo where Bartz lived.

Lamb said he shared in the relief of the community in northwestern New Mexico as word spread that someone was in custody.

"Now we can approach the funeral with a sense of relief and a better focus on the grieving process for Sister Marguerite and the celebration of her life," he said.

Investigators remained tightlipped about details of the crime, but said preliminary autopsy results show Bartz sustained substantial trauma, likely as a result of a violent confrontation with her killer or killers.

FBI spokesman Darrin Jones said agents were 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.

Diocese officials said the community has questions about whether the crime could have been the result of a robbery, if it was gang-related or possibly connected to a break-in at the parish last month.

FBI investigators have combed Bartz's home for evidence and a mini-SUV she had used was transported to Albuquerque for processing by investigators. It arrived Wednesday with a sheet draped over the driver's side, covering the window. The FBI has said Bartz's murder apparently happened Halloween night or early Sunday.

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

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

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