NAVAJO, N.M. (AP) -- A vehicle belonging to a nun slain on the Navajo Indian reservation has been recovered in Arizona, authorities said Tuesday.

FBI spokesman Darrin Jones said he cannot disclose where in Arizona the vehicle was located. He said authorities were waiting on autopsy results and hope to release additional details surrounding the case later in the day.

The body of Sister Marguerite Bartz was found dead in her residence at St. Berard Mission Church after she failed to show up to Sunday Mass in the small community of Navajo, on the New Mexico-Arizona border.

Investigators believe the 64-year-old was killed sometime between Halloween night and Sunday morning.

On Monday, authorities asked for help from the public in their search for Bartz's vehicle, a beige 2005 Honda CR-V with New Jersey license plates. FBI agents also want anyone who spoke to Bartz on Halloween night to contact them.

"We would very much like the public's assistance if they saw anything or heard anything," Jones said. "You never know what little detail may help."

Authorities and officials with the Diocese of Gallup, which oversees the parish in Navajo, said they were not sure whether Bartz or the church were the target or if the attack was a random act.

Bartz was one of more than a dozen Sisters of the Blessed Sacrament who are ministering within the Diocese of Gallup, which spans 55,000 square miles in New Mexico and Arizona.

The diocese said Bartz was born in Plymouth, Wis. She entered the order in 1966 from Beaumont, Texas, and professed final vows in 1974. She had ministered in Massachusetts, Louisiana and in several communities around New Mexico before ending up at St. Berard in 1999.

A spokesman for the diocese said the bishop has been in contact with the Sisters of the Blessed Sacrament, and those at the parish in Navajo were shaken up about the incident.

The diocese said there is usually another sister who lives at the residence with Bartz but she was out of the state at a meeting and Bartz was alone.

"She was known to be a woman always passionate for justice and peace, and the life she lived would tell us that she would respond to this incident with a spirit of forgiveness toward whoever is responsible for these acts," the diocese said in a statement Monday.

(Copyright 2009 by The Associated Press. All Rights Reserved.)