The former mayor, accused of triple murder, became enraged when his wife told him she had been sexually abused, police said

The former mayor of a small South Dakota town who is accused of triple murder became enraged shortly before the triple shooting last week when his wife told him that a neighbor had sexually abused her, court documents show.

The men were killed on May 27 in Centerville, a town of fewer than 1,000 people about 40 miles south of Sioux Falls.

Shortly before her death, Jay Ostrem’s wife told him that a neighbor with whom she had been drinking on May 23 had forcibly kissed her and exposed himself in the process, according to an affidavit from a special investigator with the South Dakota Division of Criminal Investigation.

The accusation caused Ostrem to “leave the house in anger,” the affidavit states.

The document states that Ostrem’s wife denied that her husband had said anything before he left, saying she did not know where he was going or whether he was armed.

Zach Frankus called 911 and reported that his brother had been shot “with a shotgun,” the affidavit states. He told the dispatcher his brother had been shot by “a guy from across the street,” the police document states.

Frankus stated that he had also been shot and then broke off communication with the operations center, the affidavit states.

When officers entered the home, they found three men dead with apparent gunshot wounds. The affidavit identified them as Paul Frankus, 26, his brother Zach Frankus, 21, and a third man, Timothy Richmond, 35. Richmond’s relationship to the Frankus brothers was not clear.

Ostrem’s wife told him Paul Frankus attacked her, the affidavit states.

Ostrem, 64, was arrested shortly after the shooting as he was walking on the street where he lived. An AR-style rifle was lying on the ground next to him and a handgun was in his pocket, the affidavit said. An officer saw Ostrem exit the garage of the home where the three men were shot, the affidavit said.

Ostrem was being held on $1 million bail in the Minnehaha County Jail on Monday and is charged with three counts of first-degree murder, according to jail records and a statement from Attorney General Marty Jackley.

A spokesman for Jackley’s office said Monday that the investigation was ongoing and declined to comment further.

It was still unclear on Monday evening whether Ostrem had hired a lawyer. Ostrem’s wife could not be reached for comment.

Ostrem became mayor of Centerville in May 2009 and the city council accepted his resignation in November 2011, city documents show.

The documents did not say why Ostrem resigned.

In July 2010, the city’s former police chief filed a federal lawsuit against Centerville and Ostrem.

“Ostrem also made gender-related comments … that were unwelcome and demeaning,” the lawsuit states.

The lawsuit alleges that he made comments about menstruation being a “man’s job” and the inability of women to be as successful as men.

A mediation took place in July 2012, and the case was subsequently dismissed, according to court records. The Sioux Falls Argus Leader reported that the two reached a settlement during the proceedings.