SANTA MONICA, Calif. -- A suspect who was taken into custody in Santa Monica after authorities discovered an arsenal in his car that included explosive chemicals and assault rifles early Sunday morning was on probation.Police said 20-year-old James Howell of Indiana was arrested after officers found three assault rifles, high-capacity magazines and ammunition, along with a 5-gallon bucket with chemicals capable of creating an explosive device in his vehicle.Officials responded to the 1700 block of 11th Street after receiving a call from a concerned citizen after Howell knocked on their door and window.Authorities made contact with Howell, who was sitting in a car registered in Indiana, who told them he was there for the Los Angeles Pride festival.The bomb squad was called to the scene to render the car and surrounding area safe. The police department was coordinating the investigation with the FBI.According to police reports obtained by ABC7, Howell was arrested after he threatened to shoot his neighbor in Indiana with a .44 caliber Smith and Wesson on Oct. 15, 2015.The Indianapolis Star reports Howell was charged with a felony charge of pointing a firearm and a misdemeanor charge of intimidation.In April, Howell pleaded guilty to intimidation, and the Indianapolis Star reports the pointing a firearm charge was dropped.Howell was sentenced to one year of probation, according to the Indianapolis Star, and part of the condition was he would "forfeit all weapons" during the one-year period.Authorities said the investigation into Sunday's arrest was ongoing, adding that the arrest had no connection to the Orlando nightclub mass shooting that took place early Sunday morning.According to police records, Howell was being held on $500,000 bail and was scheduled to appear in court on Tuesday.Anyone with more information on the incident was asked to call Det. Dereck Leone at (313) 458-8949.