"He wanted to know what I was trying to pull, what I was trying to put over on people, and so I was just quiet. I told him I wouldn't tell him anything and I wouldn't say anything until I got out of the Army, and I left," Henry says.
Then he ended his silence: He published his account of the massacre in the debut issue of Scanlan's Monthly, a short-lived muckraking magazine, which hit the newsstands on Feb. 27, 1970. Henry held a news conference the same day at the Los Angeles Press Club.
Records show that an Army operative attended incognito, took notes and reported back to the Pentagon.
A faded copy of Henry's brief statement, retrieved from the Army's files, begins:
"On February 8, 1968, nineteen (19) women and children were murdered in Viet-Nam by members of 3rd Platoon, 'B' Company, 1st Battalion, 35th Infantry .
"Incidents similar to those I have described occur on a daily basis and differ one from the other only in terms of numbers killed," he told reporters. A brief article about his remarks appeared inside the Los Angeles Times the next day.
Army investigators interviewed Henry the day after the news conference. His sworn statement filled 10 single-spaced typed pages. Henry did not expect anything to come of it: "I never got the impression they were ever doing anything."
In 1971, Henry joined more than 100 other veterans at the Winter Soldier Investigation, a forum on war crimes sponsored by Vietnam Veterans Against the War.
The FBI put the three-day gathering at a Detroit hotel under surveillance, records show, and Nixon administration officials worked behind the scenes to discredit the speakers as impostors and fabricators.
Although the administration never publicly identified any fakers, one of the organization's leaders admitted exaggerating his rank and role during the war, and a cloud descended on the entire gathering.
"We tried to get as much publicity as we could, and it just never went anywhere," Henry says. "Nothing ever happened."
After years of dwelling on the war, he says, he "finally put it in a closet and shut the door."
Unknown to Henry, Army investigators pursued his allegations, tracking down members of his old unit over the next 3 1/2 years.
Witnesses described the killing of the young boy, the old man tossed over the cliff, the man used for target practice, the five unarmed women, the man thrown beneath the armored personnel carrier and other atrocities.
Their statements also provided vivid corroboration of the Feb. 8, 1968, massacre from men who had observed the day's events from various vantage points.
Staff Sgt. Wilson Bullock told an investigator at Ft. Carson, Colo., that his platoon had captured 19 "women, children, babies and two or three very old men" during the Tet offensive.
"All of these people were lined up and killed," he said in a sworn statement. "When it, the shooting, stopped, I began to return to the site when I observed a naked Vietnamese female run from the house to the huddle of people, saw that her baby had been shot. She picked the baby up and was then shot and the baby shot again."