An internal inquiry had confirmed an officer's widely publicized charge that members of the 173rd Airborne Brigade had tortured detainees in Vietnam.
"This package provides sufficient material to impeach this man's credibility; should this need arise, I volunteer for the task," wrote Col. Henry H. Tufts, commander of the Army's Criminal Investigation Division.
Now, declassified records show that while the Army was working energetically to discredit Herbert, military investigators were uncovering torture and mistreatment that went well beyond what he had described.
The abuses were not made public, and few of the wrongdoers were punished.
Tufts' agents found that military interrogators in the 173rd Airborne repeatedly beat prisoners, tortured them with electric shocks and forced water down their throats to simulate the sensation of drowning, the records show.
Soldiers in one unit told investigators that their captain approved of such methods and was sometimes present during torture sessions.
In one case, a detainee who had been beaten by interrogators suffered convulsions, lost consciousness and later died in his confinement cage.
Investigators identified 29 members of the 173rd Airborne as suspects in confirmed cases of torture. Fifteen of them admitted the acts. Yet only three were punished, records show. They received fines or reductions in rank. None served any prison time.
The accounts of torture and the Army's effort to discredit Herbert emerged from a review of a once-secret Pentagon archive.
The collection — about 9,000 pages — was compiled in the early 1970s by an Army task force that monitored war crimes investigations. The files, examined recently by the Los Angeles Times, include memos, case summaries, investigative reports and sworn witness statements.
Those and related records detail 141 instances of detainee and prisoner abuse in Vietnam, including 127 involving the 173rd Airborne.
The Army task force, created after journalist Seymour Hersh exposed the 1968 My Lai massacre, served to give military brass and the White House early warning about potentially damaging revelations.
The war crimes records were declassified in 1994 and moved to the National Archives in College Park, Md., where they went largely unnoticed.
The Times examined most of the files before officials removed them from the public shelves, saying they contained personal information that was exempt from the Freedom of Information Act.
Other records were taken by Tufts in the 1970s and donated after his death to the University of Michigan.
The two collections do not provide a complete accounting of prisoner abuse during the Vietnam War. They contain only cases reported to military authorities and flagged for special attention by the Army chief of staff's office or taken home by Tufts. But they represent the largest pool of such records to surface to date.
Retired Brig. Gen. John H. Johns, a Vietnam veteran who served on the task force, said the files provided important lessons for dealing with the prisoner abuse scandal in Iraq.