AUSTIN – Police officer Ramiro Martinez wasn't supposed to be at work until 3 p.m., but when he heard the noon television news of trouble at the University of Texas, he figured his colleagues at the scene could use some help.

Austin History Center

Ramiro Martinez, APD officer. August 9, 1966.

He called in from home. His instructions were to go to the campus and work traffic, keeping people away from the area around the landmark 307-foot University of Texas Tower.

A gunman was on the 28th-floor observation deck and shooting people on the streets, 231 feet below. Several people already had been hit.

Mr. Martinez, then 29, forever would be linked with what at the time – 40 years ago Tuesday – became the worst mass killing in American history.

Sixteen people were killed and 31 wounded that day – Aug. 1, 1966.

Mr. Martinez, known as Ray, was one of the two officers to kill the gunman, 25-year-old Lake Worth, Fla., native Charles Whitman, a former Eagle Scout, former Marine and former University of Texas student.

"Why deny history?" says Mr. Martinez, now 69 and retired. "It's something that happened and something that's part of my life."

Mr. Martinez and another officer, Houston McCoy, fired the shots that took down Mr. Whitman an hour and a half after the deadly siege began. Before his murderous attack from the top of the tower, Mr. Whitman had stabbed to death his mother at her Austin apartment and his wife at their Austin home.

In 2001, a Fort Worth man died of what physicians said were complications from a gunshot wound inflicted that day by Mr. Whitman, bringing the death toll to 17.

For Mr. Martinez, who eventually became a Texas Ranger, "Time has gone so fast."

Forty years later, he remembers reaching the campus, about four miles from his home at the time. When he saw that other officers already had traffic rerouted, "I decided I might as well go to the tower to assist."

It was an era before portable radios and cellphones. Before specialists like SWAT teams.

"I had to run by dead and wounded people," Mr. Martinez said. "There was no communication with anybody. It's all of my own doing, but I was hoping to assist. I figured there already would be a team there."

AP

University of Texas Tower, the day after Charles Whitman's shooting rampage. August 2, 1966

He took the elevator to the 27th-floor reception area and hooked up with several officers, including Mr. McCoy. There also was carnage. A receptionist had been fatally beaten by Mr. Whitman. Two tourists from Texarkana had been fatally shot.

Mr. Whitman had barricaded the door to the observation deck with a hand truck he'd used to carry a footlocker filled with supplies. Mr. Martinez forced the door open and emptied his police-issue .38-caliber pistol toward the carbine-carrying killer. When Mr. Whitman swung to return fire, Mr. McCoy aimed his 12-gauge shotgun at his white headband and fired twice.

"There was no way he was going to come down alive," Mr. Martinez said last week. "I'm pretty sure he had predetermined he was going to die."

Flags will fly at half-staff on the University of Texas campus on Tuesday, the 40th anniversary of the UT Tower shootings. The school also will receive a donation of artifacts related to the tragedy. Some details:

Historical notes: UT's Center for American History will accept the donation of personal papers kept by Allen Hamilton, then the university's police chief.

What's in the papers: They include a number of photocopied documents and some original reports submitted by officers who responded to the scene. There are also some original vehicle information documents signed by the killer, Charles Whitman, when he was a student in 1965, some memos about his campus parking violations and a parking fee receipt.

Securing history: A Half Price Books store in Austin, having recognized the historic value of the documents, bought the papers from a relative of Mr. Hamilton.