ES, I looked at several stories, the jist of the preliminary investigation was that nothing was found that would lead to a formal investigation.

There are a lot of questions about Kerry's actions in Vietnam, among them being why he was not given an honorable discharge until the late '70's. (Even if one is discharged from active duty to the reserve components you get a discharge of some sort) The normal route leading to such a late discharge is an OTH (Other than honorable or General under honorable conditions) being challenged leading to an honorable discharge several years after the fact, which is among the many reasons there are a lot of people who question his service record. Given the timeline of the "Winter Soldiers" issues, and given the fact that under the UCMJ it is illegal to participate in partisan political activities (which Winter soldiers most certainly was) while in the service, I would question what the original discharge he was given was. Kerry also caused breaches of the UCMJ while he was campaigning, using uniformed servicemen as political props at campaign events, which is illegal under the hatch act.