"It has generated confidence that this would be an impartial investigation," said Mario Merida, a security analyst and newspaper columnist.
Leaders of the military, which once ruled Guatemala and is closely watched at delicate moments, have stayed in the background, making it clear that their only role this time would be to defend the constitution. The statements have taken the air out of concern that the scandal could provoke a military coup.
Colom's foes have asked Congress to strip the president of official immunity from prosecution while pressing him to step aside. Guatemala does not have an impeachment process.
But the president's opponents also have broadened their message by including wider concerns, such as reducing violence and reforming the nation's deeply troubled justice system.