text:  A law enforcement source tells our colleague, Kerry Johnson, that investigators believe the gun used in the shooting was bought by Crooks' father about six months ago. And also at least one explosive device, one that was believed to be workable, was found in the suspect's vehicle. Crooks, of course, is dead. The Secret Service killed him when they returned fire. One last thing, President Biden and Vice President Harris are getting an updated briefing on the investigation now from the attorney general, the FBI director and others.