A Louisiana triple-murder suspect, believed to be headed to California, was captured in Lewiston Friday night.

Lewiston Police say Robert McCoy, 34, was caught riding as a passenger in a Swift Transportation truck in the Normal Hill area.

McCoy is the prime suspect in the slayings of his estranged wife’s 17-year-old son and her parents Monday night in Bossier City, Louisiana. He is believed to have killed them during a search for his wife, who remains in protective custody.

Bossier City police say McCoy eluded authorities for nearly four days by fleeing to Texas, Arkansas and Washington, traveling as a passenger in 18-wheelers. Authorities tracked the truck McCoy was in to Spokane and notified Idaho State Police he was headed their way.

Officers spotted the vehicle and both LPD and ISP patrol cars surrounded it in the 500 block of Sixth Avenue. McCoy was taken into custody without incident, while the truck driver was not charged.

A .380-caliber pistol was retrieved from behind the passenger seat of the truck, and Louisiana authorities believe the gun was used in the Bossier City murders.

McCoy was booked into the Nez Perce County Jail on three murder warrants and may face a charge of unlawful flight to avoid prosecution. McCoy will be extradited back to Louisiana this week.