On Tuesday, the gray-haired scientist sat perched on the edge of a desk in a small corner of Sparks. Looking up, his eyes met a class of 12 high school sophomores and seniors.
"Who wants to read about John Wayne Gacy?"
Turning to the page in their text about the Chicago killer of 28 young boys, the forensic science students at Excel Christian School were eager to oblige.
Siefried stepped into the swirling world of FBI and CIA forensic investigations in 1971, a bright-eyed college graduate looking for some excitement. He found it. Seven years of rotting corpses, organized crime, kidnapping and extortion investigations left their mark on the man who now shares his knowledge with local students. Siefried is in his first year teaching a forensic sciences class at the private school. He previously used his background in the sciences to teach physics. He also teaches chemistry at the school.
"Some of this stuff, you can't believe it really happens," said 15-year-old student Morgan Sanders, speaking of the course content.
On Tuesday, students learned how to secure a crime scene and properly initiate an investigation.
The class also incorporates biology, physics and chemistry into the study of true-to-life crime cases and counts for a required science credit at the school.
"The biology class was full," Sanders said. "So I enrolled in this one. Now all my friends want to get into it."
Sanders said that while the class is interesting, she is mulling over becoming a marine biologist and loves the science aspect of the forensics class.
And while Siefried said some students are interested in pursuing the career of a forensic investigator, he added that his goal isn't to breed only future crime investigators.
"I want them to explore the sciences and know how they work in everyday life," Siefried said.
Siefried's own path to federal investigations work didn't start in the classroom. The New England man had just graduated from the New Hampshire Technical Institute with a bachelor's degree in electronics when the opportunity arose.
"My mom heard an ad on TV that the FBI was hiring," the light-hearted man said with a smile. "Nine months later, the next thing you know I was there."
In June 1972, just after being hired, five men broke into the Watergate Complex in Washington D.C. leaving a dark mark on a presidential administration along with plenty of wiretapping devices for Siefried to investigate.
While still with the FBI, Patty Hearst was kidnapped. The granddaughter of publishing icon William Randolph Hearst, she resurfaced months later as a bank robber and icon for the Symbionese Liberation Army — a revolutionary group that murdered and pillaged in the name of the underprivileged.
Hearst became a public relations icon for the group, even robbing a bank at gunpoint, but later claimed that she was tortured and forced into compliance.
Siefried analyzed the propaganda recordings and broadcasts from the group to see if there was any stress in Hearst's voice, signaling duress.
The woman was imprisoned for almost two years before her sentence was commuted by President Jimmy Carter. She was later granted a presidential pardon by President Bill Clinton in his last official act before leaving office.
The decision to trade in a life of investigation for a life of classroom teaching came for Siefried when his wife, a federal employee, got a government position in northern Nevada.
Since his days with J. Edgar Hoover, the agent turned teacher has been coaching soccer and teaching physics, chemistry and physical education in Sparks schools.
This semester will be Siefried's second year at Excel Christian School where he will spend his days sharing his love of science and sports.
"As much as I loved working (for the FBI and CIA), this is my calling," Siefried said. "(In that job) within the day, you saw the results of your work. I see that here too (with the students). It is more rewarding than anything I have ever done."
The class is the only one of its kind in the area. Siefried hopes to have FBI agents lecture to the class along with Washoe County Crime lab employees.
"I want them to teach the kids first hand what they do," Siefried said, just as the former agent is sharing his first-hand knowledge.