ROME — Less than two months ago, Deputy Brig. Mario Cerciello Rega was married in a small church in the town of Somma Vesuviana, near Naples, Italy.

On Monday, the nation watched as a funeral for Brigadier Cerciello Rega was held in the same church, three days after he was stabbed to death in the aftermath of a bungled drug deal in Rome, where he worked as an officer of the carabinieri, or military police. The police say that two American teenagers who were arrested have confessed to the attack.

The funeral became a state affair, with Italy’s two deputy prime ministers, Matteo Salvini and Luigi Di Maio, and a slew of national and local officials standing alongside his widow as the ceremony was broadcast on national television. In a eulogy, Gen. Giovanni Nistri, the commander of the carabinieri corps, praised the slain officer for demonstrating “the values that a carabiniere should aspire to.”

Yet even as the country mourned, a widely circulated image of one of the suspects sitting handcuffed and blindfolded before his police interrogation raised questions about the validity of his confession. The photograph has been highlighted on social media and in Italian news coverage, prompting a debate over how the Americans have been treated.