Tesla coil.jpg

A demonstration of a Tesla coil, projecting "lightning" across a room.

(Wikipedia Commons)

Samuel David Dufner

A classroom science demonstration apparently went wrong last week, leading to the arrest of a South Salem High School teacher.

Samuel David "Sam" Dufner, 37, of Monmouth was arrested Tuesday by Salem police for allegedly burning "I (heart) Mom" into several students' arms with a Tesla coil.

Dufner was booked into the Marion County Jail on suspicion of criminal mistreatment, a Class C felony. He posted a $2,000 security deposit against bail of $20,000 and was released.

Meanwhile, Dufner was placed on paid administrative leave by the Salem-Keizer School District, said Jay Remy, district spokesman.

Dufner did not return a phone message seeking comment.

Lt. Steve Birr, Salem Police Department spokesman, said a concerned parent contacted authorities late Friday regarding an experiment in Dufner's science classes the previous day. After investigating, police arrested Dufner without incident at the school.

"By and large, the burns aren't bad at all," Birr said. "But one student's arm is a little swollen and red."

None of the students required medical care.

Birr said police still are trying to determine how many students were subjected to the experiments, which were conducted in several classes.

Nikola Tesla

The Tesla coil, a frequent prop in science fiction and horror films, was developed by inventor Nikola Tesla in 1891 in an attempt to wirelessly transmit electricity over long distances. Though it never proved practical, the Tesla coil remains a science class favorite for its elaborate displays of "lightning."

Birr said Dufner reportedly held the Tesla coil 1 to 2 inches from the students' arms and manipulated it to burn in the I-heart-Mom messages.

According to Salem-Keizer records, Dufner was hired in 2006 and has worked as a South Salem High science teacher since then.

"I think this Tesla coil demonstration shows a lack of judgment," Birr said. "This not the crime of the century, but we expect more from our teachers."

-- Rick Bella rbella@oregonian.com

503-294-5915; @southnewshound