PIERCE, Colo. — Scrap metal thieves are not known for sophistication. From drug addicts in the 1970s ripping copper plumbing from walls to scrap-yard regulars of more recent years who proffer whatever fell off a truck, stealing hunks of coil or reinforcing bar has mostly been about having a strong back and a willingness to get dirty, law enforcement experts say.

The thieves who struck the Tucker dairy farm this year were different.

Start with the possession of a cherry-picker utility truck, which they apparently deployed to reach the tops of the 18-foot-tall poles bringing electricity to the farm. The thieves knew how to take down fully-charged electricity lines without getting killed and then, the police said, had a big enough team to roll up hundreds of pounds of wire from the half-mile-long crime scene and make their getaway. The case has not been solved.

“In the past, you had amateurs,” said Charles R. Tucker, 61, who runs the family operation with his brother, Iven, 62. “These guys were pros.”

Metal crime is being nudged into the 21st century by technology, high commodity prices and bad economic times, law enforcement officials and insurance experts say.