“Did you take that from me, Hallie?” Mr. Biden texted after learning she had removed the gun from the lock box because she feared he might kill himself with it. He went on to suggest that the weapon might be discovered by the F.B.I., which he referred to using an expletive.
Mr. Lowell suggested he might sharply question Ms. Biden’s version of events on cross-examination.
If prosecutors began with a focused outline of their case, their presentation soon slowed with the testimony of their first witness, an F.B.I. agent who served as a kind of docent. The agent, Erika Jensen, guided the jury through exhibits and played extended audio clips of Mr. Biden reading chapters of “Beautiful Things,” his autobiography, detailing his addiction to crack cocaine at the time he bought the gun.
The sound of Mr. Biden’s voice echoing through the courtroom, as he listened tight-lipped, was jarring and initially transfixed the courtroom. But after about a half-hour, attention drifted, even, it seemed, among prosecutors.
At one point, Mr. Hines asked Ms. Jensen, “We’re still in Chapter Eight, right?”
The trial, which is expected to last about a week, promises to be an excruciating personal ordeal for the Biden family.
On Tuesday, Mr. Hines said prosecutors planned to summon Hallie Biden and another woman Mr. Biden was romantically involved with, Zoe Kestan, in addition to his former wife, Kathleen Buhle. He also plans to call Gordon Cleveland, an employee at the Delaware gun store where Mr. Biden bought his weapon, and two expert witnesses who will testify on drug residue and other forensic evidence.
