Nelson thanked the Defense Department for its work to locate the remains of Speicher as of late, which were identified in Iraq on Sunday, but shamed the agency for its work in the 1990s.
"I really thank the Department of Defense for staying on this," Nelson said during an appearance on Fox News. "They dropped the ball in the 1990s, but fortunately, we have the evidence now."
Nelson, a member of the Senate Armed Services Committee, has long taken an interest in determining the fate of Speicher, who went missing after being shot down in 1991 during the early days of the first Gulf War.
"It got lost in the bureaucracy," Nelson said of the Speicher case's handling by the Pentagon. "They just forgot about it."
"We walked away from a downed pilot," the Florida Democrat added. "18 years is a long time to through through the emotional ups and downs on this-or-that lead."