Four were killed by Jason Hamilton whose deadly rampage was unleashed on many people he knew.
Police say Hamilton began by killing his wife and then shooting up the courthouse where she worked as a custodian. He ended the spree by killing himself in the First Presbyterian Church, after fatally shooting the caretaker he knew from his job as a janitor.
Hamilton, 36, was also known to local law enforcement officers. He had been arrested for domestic violence, had attempted suicide, and warned that he wanted to kill himself in a way that would harm others.
But in the end he left no obvious reason for the violence.
"We have not found any note," said David Duke, assistant chief of the Moscow Police Department. "We do not have any motive at this time. We have no idea."
Police said they had no doubt Hamilton was the one responsible for the carnage. "There are no other suspects," Duke said Monday.
Hamilton shattered the quiet of this bucolic college town with some 200 gunshots late Saturday night and early Sunday morning. The community has some 20,000 people and includes the University of Idaho.
"This is a tragic event, but an aberration here," Mayor Nancy Chaney said Monday. "We are a small, close-knit community where we pay attention."
Hamilton had been drinking at a bar in town on Saturday night, showing no sign of distress, police said.
About 10 p.m. Saturday, he returned to his home about 3 miles (5 kilometers) from town and fatally shot his 30-year-old wife, Crystal, in the head, Duke said.
Hamilton then drove downtown to the Latah County Courthouse, armed with two semiautomatic rifles that he apparently bought before his legal troubles began. Standing outside the courthouse, which houses the sheriff's department, Hamilton fired some 125 bullets into the sheriff's dispatch center and into vehicles in the parking lot shortly after 11 p.m. Saturday.
He shot and killed one law enforcement officer and wounded Pete Husmann, 20, a University of Idaho mechanical engineering student from Coeur d'Alene. Husmann had armed himself and run to the sound of the shots. Two other law enforcement officers were wounded, Duke said.
Then Hamilton moved across the street to the First Presbyterian Church.
Church sexton Paul Bauer, 62, was shot while he tried to call police; dispatchers could hear the gunfire, Duke said.
Hamilton fired an additional 60 to 80 rounds from inside the church before killing himself around 1 a.m. Sunday, Duke said. An AK-47 rifle was found next to Hamilton's body.
While Hamilton appears to have at first targeted law enforcement, Duke said there was no sign that he had a particular grudge against them.
According to Duke, Hamilton in 2005 had been arrested for domestic violence against a woman with whom he was having an extramarital affair, and sentenced to two years probation. He was not to possess firearms during that time, but possessed the rifles before that charge was filed, Duke said.
On Feb. 16, Hamilton attempted suicide by overdosing on anti-anxiety medication, and was evaluated twice for involuntary mental health commitment, Duke said.
Hamilton told his first doctor that if he were really to commit suicide, he would do it through a mass shooting or bombing in which others would die, Duke said. But he later said he was not serious, Duke said.
Hamilton was judged not to need involuntary commitment, and was released, Duke said.
Hamilton was in court May 15 for violating the conditions of his probation on the domestic violence charge by halting his mental health counseling, Duke said. The case was continued until June 15.
Duke said police found Crystal Hamilton's body Sunday morning, but did not release the information so relatives could first be notified. She had worked at the courthouse janitorial department since 2000.