SPOKANE, Wash. --- Spokane Police arrested a felon on Thursday after finding him in possession of 36 firearms.

Robert W. Crampton, 62, was convicted of three felony criminal law violations in 2013 after getting into a shootout with the Las Vegas Police Department, according to SPD. Officials said Crampton was “reportedly suicidal” at the time of the shootout, and shot several times but survived.

Detectives in Spokane began to investigate Crampton after getting a tip that he was in possession of several firearms, according to SPD. The Targeted Crimes Unit, which works with Federal Bureau of Alcohol, Tobacco, and Firearms, as well as the Washington State Department of Corrections, executed a search warrant at Crampton’s home.

SPD reports they found 36 firearms, as well as 35,000 to 40,000 rounds of ammunition, magazines and ballistic vests.

Officials said Crampton had purchased the guns before becoming a convicted felon, and was “somehow able to obtain possession of the firearms” after getting out of prison and moving to Washington State.

Crampton was booked on several counts of unlawful possession of firearm, according to SPD. He is being held in the Spokane County Jail.

Officials from SPD said detectives are continuing their investigation “as to the legality and origin of firearms.”