Chuck Mawhinney, a Marine Corps veteran who became the deadliest sniper in the corps’ history while serving in the Vietnam War, died on Monday at his home in Baker City, Oregon at the age of 75.

Mawhinney’s Marine Corps career began at Camp Pendleton, where he attended the base’s sniper scout school.

From there he was deployed to Vietnam, where he battled the North Vietnamese Army and Vietcong guerilla fighters. The Marine Corps credited Mawhinney with 103 confirmed kills, as well as 216 “probable” kills that could not be confirmed due to the danger of the area of operations, over a 16-month period in 1968.

According to American Rifleman, Mawhinney primarily carried a Remington M40 sniper rifle, typically firing from a distance of 300 to 700 yards. Some shots were made from as far away as 1,000 yards.

One of Mawhinney’s most legendary engagements came when his unit received intelligence that a battalion sized NVA regiment was approaching their position. Mawhinney, who knew the area well by this point, told his commanding officer that he knew a place on the river where the water was four feet deep and was certain the enemy would cross there.

His commanding officer was initially hesitant to let Mawhinney and his spotter watch the crossing, but the legendary Marine ultimately talked him into it.

“It was during the monsoon season, and the river had just dropped after heavy rains. It was still cloudy, but sheet lightning up in the clouds lit everything up like starlight. We sneaked into a place near the ford and sat in an eddy-cut eroded into the bank. Pretty soon an NVA scout started across the river,” Mawhinney told American Rifleman. “I didn’t want to let him get into the elephant grass on the other side, and had the scope on his head—about all that showed above the water—but when he got close to the grass he stopped. He stood there for a little bit, looking around, then waded back across the river the way he’d come.”

“Pretty soon a bunch more showed up, and when they got out into the water I started shooting, killing 16, all with head shots, until they stopped coming. I shot the rifle 16 times. Evidently that intimidated the rest of the unit, and they all pulled out during the night. The river’s current carried away all but two of the NVA I’d shot. That was on February 14th of 1969, St. Valentine’s Day,” the Marine legend recalled.

“It was the ultimate hunting trip: a man hunting another man who was hunting me,” Mawhinney, an experienced hunter, told the Los Angeles Times in a 2000 interview. “Don’t talk to me about hunting lions or elephants; they don’t fight back with rifles and scopes. I just loved it.”

The details of Mawhinney’s career were not fully known until he told his entire life story from his own perspective in 2023 in The Sniper: The Untold Story of the Marine Corps’ Greatest Marksman of All Time.