A satellite engineer who sold military secrets to an undercover FBI agent he believed to be a Russian spy was sentenced Monday to five years in federal prison.

In handing down the punishment for Gregory Allen Justice, U.S. District Judge George H. Wu added a few months to what sentencing guidelines recommended, saying he found the crimes “extremely troublesome.”

Wu, however, rejected prosecutors’ request for more years behind bars after concluding there was insufficient evidence to support a government allegation the Culver City scientist also had been plotting to use a potent drug to murder his wife.

“This defendant sold out his employer and betrayed his country in exchange for a few thousand dollars,” said acting U.S. Atty. Sandra R. Brown. “His actions posed an imminent threat to our national security … and a person who was willing to sell important information to a foreign power will now serve a considerable amount of time in a federal prison.”