A former U.S. Marine accused of planning a Christmas holiday terrorist attack on San Francisco’s iconic Pier 39 in 2017 before he was foiled by the FBI was sentenced on Monday to 15 years in prison.

Everitt Aaron Jameson, a California 27-year-old who pleaded guilty in June to attempting to provide material support to the Islamic State, also faces a life term of supervised release, according to a Justice Department news release regarding U.S. District Judge Lawrence O’Neill’s decision.