WATERLOO - Mark Langenwalter's first night as a Waterloo police officer wasn't too exciting.

Working second shift as an auxiliary patrolman, Langenwalter spotted a car going 10 mph over the speed limit.

It had been a quiet night, and it was toward the end of the shift with no other calls, so he turned on his flashing lights and pulled over the vehicle.

"The speeder turned out to be another police officer who was late for work," said Langenwalter, who later became a full-time officer.

He let the late third-shift officer off with a warning.

Langenwalter's second night on the beat started hot with a shooting at what was then the Purple Martin gas station on Franklin Street.

The smell of gun smoke was fresh in the air when Langenwalter and his partner pulled up. There were shell casings on the ground, and the gas station attendant was hiding behind a car while the attacker yelled at him.

"I knew right then and there that this was no ordinary job," said Langenwalter. Backup arrived soon, and the gunman was charged with attempted murder.

Langenwalter retired in November at the rank of sergeant after 30 years with the Waterloo Police Department.

Over the years, he worked for patrol, investigations, internal affairs and community services where he produced the government access cable television show "Waterloo Police Beat" in 2000 and had a hand in designing the graphics on the department's fleet of black-and-white squad cars.

"I'm at the point in my career where I've actually arrested grandchildren of people I arrested when I first became an officer," he said. He notes the department now has 20 officers that were born after he started his law enforcement career.

Born in San Diego, Calif., to the son of an Iowa native, Langenwalter moved to Waterloo with his family when he was 3 or 4.

He graduated from Columbus High School in 1971 and joined the U.S. Army, where he was assigned to a Nike Hercules surface-to-air missile battery in Anchorage, Alaska.

Upon returning to Waterloo in 1974, he landed a job with the city engineering department.

After a few years as a surveyor, he found the assignment tedious, and a friend who was a police officer suggested he try a career in criminal justice.

Langenwalter opted to "test drive" the job, taking a volunteer spot as an auxiliary officer, which are now called reserve officers. Not long after that, he became a full-time officer.

He liked the variety of the job, and after three decades still occasionally saw things that amazed him.

"There were no two days the same in 30 years," Langenwalter said.

Along the way, he earned the rank of major in the Iowa Air National Guard. He was with the 132nd Fighter Wing based in Des Moines and was the commander of its Security Police Squadron for most of his career before retiring from the military in 1999.

Langenwalter has four children, two stepchildren and 12 grandchildren.

He and his wife, Elaine, are moving to Lake City, Minn., where they plan to spend the summer months sailing on Lake Pepin.

Contact Jeff Reinitz at (319) 291-1578 or jeff.reinitz@wcfcourier.com.