Nearly two weeks after the assassination attempt on former President Donald J. Trump, there’s still no official report from the Trump campaign or from state or federal governments about what caused the wound on his right ear.

This lack of clarity has left the issue unsettled and fueled speculation online about whether he was hit by a bullet or shrapnel — or perhaps something else.

But a detailed analysis of bullet trajectories, footage, photos and audio by The New York Times strongly suggests Mr. Trump was grazed by the first of eight bullets fired by the gunman, Thomas Crooks. Subsequent bullets wounded two rally goers and killed a third.

What has helped stoke confusion is that Mr. Trump himself has said he was hit by a bullet, but his campaign has not released any official medical reports, nor has Mr. Trump’s current physician weighed in.

Instead, the campaign has posted a memo from Mr. Trump’s former White House physician, Ronny L. Jackson, now a Texas congressman and outspoken ally of the former president, that says he was struck by a bullet on his right ear.

The Secret Service, which was responsible for the security at the event, has declined to comment.

The F.B.I. said it was examining numerous metal fragments found near the stage to determine whether a bullet — or pieces of it — had grazed Mr. Trump’s head, bloodying his ear.