OREM — Brigham Young likely could not identify who was responsible for the killing of about 120 people at Mountain Meadows until about 13 years after the event, a historian says.

Thomas G. Alexander, the Lemuel Hardison Redd Jr., professor emeritus of Western history at Brigham Young University, spoke Monday to about 50 students and professors at Utah Valley State College about historical evidence relating to the Mountain Meadows Massacre of Sept. 11, 1857, and the investigation into the matter by The Church of Jesus Christ of Latter-day Saints.

The victims of the massacre were emigrants traveling from Arkansas to California. They were killed by Paiute Indians and members of the LDS Church who were living in the area.

September is the 150th anniversary of the massacre. A film about the massacre called "September Dawn," with Academy Award winner Jon Voight, will soon be released.

Alexander said it was difficult for President Brigham Young and other leaders of the LDS Church to pinpoint exactly how the massacre transpired because of conflicting reports and rumors combined with the refusal of federal officials to allow the church to help with the investigation.

Church officials offered prosecutors $1,500 to capture the accused. They also wanted Utah Territorial Marshal John Kay deputized to help capture the accused. The federal officials refused.

"(The investigation) could have been done by 1859 if the (anti-Mormon federal) officials had been willing to go along with Brigham Young, use the money that had been offered them, get the assistance of John Kay, the territorial marshal, and allow Brigham Young to go south" to help with the investigation, Alexander said.

In the weeks following the massacre, church leaders believed the Paiutes alone killed the emigrants, Alexander said, pointing to statements by Ute Chief Arapeen and John D. Lee — who ultimately was accused of the murders.

As time passed, people began to believe local whites participated with the Paiutes in the massacre. Alexander discussed articles written in California newspapers as well as an investigation by Jacob Forney, superintendent of Indian affairs, in 1859.

In 1859, church leadership released three men from the Cedar City Stake Presidency and three people from the bishopric and replaced them with people who had not been involved in the massacre.

But it wasn't until 1870 that Brigham Young fully understood that local LDS Church members "were sent to bury people (from what they believed was an Indian massacre) then forced to participate in the massacre under (militia) and church discipline," Alexander said.

"The upshot of this is on Oct. 8 in 1870, between sessions of the general conference, (when) Brigham Young presented evidence to the Quorum of the Twelve, and they voted to excommunicate John D. Lee and Isaac Haight," a Cedar City stake president in 1857, Alexander said. Lee was the only man ever tried and executed for his part in the massacre.