DOVER, Del. — On a cold April night, under a bright moon, the body of Army Specialist Israel Candelaria Mejias arrived at Dover Air Force Base in a flag-draped aluminum case.

Mejias, of San Lorenzo, Puerto Rico, was killed by an improvised explosive device Sunday while serving in Iraq.

His return Tuesday marked the second time this week members of the media were allowed to witness a U.S. combat casualty being brought back from overseas, ending the Pentagon’s 18-year ban on such coverage.

Mejias’ body arrived shortly before 8:30 p.m. aboard a C-17 military cargo jet from Ramstein, Germany.

A little more than hour later, an eight-member team from the Army’s Old Guard in Washington, D.C., slowly walked up the rear ramp of the C-17 and into the cargo hold, where an advance team from the military mortuary at...