The Marines should be disciplined but should not be punished "for the purpose of making a statement to our partners in the region," Hunter wrote in a letter to Panetta Wednesday, The Hill reported.
"What is particularly concerning to me, as a Marine who served in both Iraq and Afghanistan, is the reported potential legal focus of the investigation and your promise that the Marines in question will be 'held accountable to the fullest extent,' which would include prison time under military law," Hunter wrote.
Texas Gov. Rick Perry, who dropped his bid for the Republican presidential nomination and endorsed former House Speaker Newt Gingrich Thursday, earlier had said the Marines who appeared on the video in question are "kids" and should not be treated as criminals.
"Most people will never know what our Marines endure unless they see it or experience it for themselves," Hunter wrote in his letter. "We owe it to these individuals and others, who put their lives on the line every day, to take into account the extraordinary conditions and danger they face when judging their actions, and put things into proper context."
Notable deaths of 2014 [PHOTOS]
Cyclist struck and dragged underneath car