SACRAMENTO (CBS SF) — A Vallejo elementary school teacher pleaded guilty Thursday to contacting a minor online for sex and faces 10 years to life in prison, federal prosecutors said.

U.S. Attorney McGregor W. Scott said 37-year-old Andrew Stephen Lund has entered a guilty plea.

According to court documents, Lund engaged in online sexual chats with a person whom he believed to be a 14-year-old girl, but who was in fact an undercover agent.

He was arrested in April 2018 by agents from Homeland Security Investigations and the Silicon Valley Internet Crimes Against Children Task Force. At the time, Lund was a fourth-grade teacher at the K-5 Glen Cove Elementary School.

He is scheduled to be sentenced by U.S. District Judge Troy L. Nunley on Dec. 5. Lund faces a mandatory statutory minimum of 10 years in prison and a maximum of life in prison, as well as a fine up to $250,000.