Four months before a married couple shot and killed two Las Vegas police officers and a bystander, the police visited their home and determined that they didn’t pose any threat, authorities said Wednesday.

Detectives were dispatched to the home of Jerad Miller in February because the Southern Nevada Counter-Terrorism Center was alerted that he had made threatening remarks to a government agency in Indiana, Kevin C. McMahill, assistant sheriff of Clark County, said during a briefing with reporters.

Miller and his wife, Amanda, were both home when the “seasoned detectives” visited to ask about the threats to the Indiana Department of Motor Vehicles, McMahill said. Jerad Miller was angry with department because his license had been suspended, but he denied threatening to shoot anyone and did not display any “anti-government or anti-police” intentions.

“The interaction with these officers was described as normal,” McMahill said. “There wasn’t anything that would have caused them any concern.”

This echoes something that happened in Santa Barbara, Calif., before a shooting there two weeks ago: A month before a gunman went on a violent rampage in a sunny beach town there, officers visited him and determined that he didn’t pose any threat.

Police also revealed more information on Wednesday about how Sunday’s violent episode, which they said began with the Millers shooting a pair of Las Vegas police officers eating lunch and ended with a shootout inside a Wal-Mart, ultimately concluded. In particular, officials changed a key part of what they had said earlier in the week.

Initially, authorities believed that Amanda Miller shot and killed her husband before taking her own life. A coroner has determined that Jerad Miller was killed by police gunfire during the firefight inside the Wal-Mart, McMahill said

McMahill said the “dramatic difference” in explaining how Jerad Miller died stemmed from the Wal-Mart’s surveillance footage, which an officer was monitoring during the shootout. Police screened a brief clip of the footage for reporters, showing the couple in what appears to be the corner of the store, with items piled around them. The footage appears to show Amanda Miller aiming her weapon at her husband and firing, but after reviewing the other forensic evidence, authorities concluded that she did not shoot him.

Investigators are still reviewing all of the video evidence captured at the CiCi’s Pizza where the officers were killed as well as footage from the nearby Wal-Mart. This graphic footage “shows you exactly how ruthless and cold-blooded these murderers were,” McMahill said.

Before taking the weapons from the two police officers in the CiCi’s, the Millers brought three guns with them on Sunday: a Smith and Wesson handgun, a Ruger revolver and a Winchester shotgun. All of the weapons were unregistered in Nevada, McMahill said. None were reported as stolen. How the couple obtained these weapons is part of the investigation, he added.

Police also had two other interactions with the Millers this year, McMahill said, both times because they were asked about reported crimes happening near them. In April, the Millers were witnesses to a report of domestic violence. And in May, just weeks before police say the Millers walked into a CiCi’s Pizza and killed two officers, the couple was contacted because an acquaintance of theirs was accused of sexual assault.

“We determined there was nothing that stood out that would have indicated to us that these suspects were anti-police or intended any harm to our police officers,” McMahill said of these encounters.

McMahill said police are not linking the shooting to the Millers visiting Cliven Bundy’s ranch earlier this year. An armed group of supporters went to Bundy’s Nevada ranch during a standoff with federal agents in April. The Millers went to the ranch but were asked to leave because of their conduct, Bundy’s son said.

“There were a lot of people with a lot of ideology” at the ranch, McMahill said. “But as you well know, in the hundreds of people who were at the Bundy ranch, these are the only two who went from ideology to action.”

Authorities are still trying to determine why the shooting occurred on Sunday, they said. Clark County Sheriff Douglas C. Gillespie said that they still believe the Millers were “acting alone.” He said investigators are poring over the material the Millers left behind and trying to figure out their thought process leading up to Sunday’s bloodshed.