It was a brutal morning for Montana law enforcement after a father and son killed a Broadwater County Sheriff's deputy and ended up in a firefight with Missoula County deputies and the Montana Highway Patrol.

Following the arrest of the two suspects, law enforcement personnel began the laborious job of evidence gathering. Unfortunately, that necessitated the closure of both westbound lanes on I-90, which backed up traffic for miles over several hours.

Montana Highway Patrol Captain Jim Kitchen said the closure was necessary to preserve the chain of evidence.

"We had to shut the highway down to do forensic mapping and we had agents coming in to process the scene and do the investigation," Kitchen said. "We understand the frustration, but I hope everybody understands that we've got a job to do and we've got to do it right."

Kitchen said the location of the incident made it difficult to reroute traffic to the eastbound lanes of I-90.

"Along with the DOT (Department of Transportation) we decided to run all the traffic one way and then back the other way," he said. "We didn't have the resources at the time to block off the highway. This is not a pre-planned construction project so we didn't have the proper equipment to go out there and do that. We apologize for the delay, but we did have a job to do. There was no way to reroute the traffic at those points because there were in choke points and no frontage roads."

Traffic finally began to move in both directions at about noon on Tuesday.