A Rockville teen’s father taught him how to build the pipe bombs the 19-year-old later provided to Collin McKenzie-Gude, who prosecutors say was planning to use the explosives to assassinate then-Sen. Barack Obama, court documents said.

Patrick Yevsukov has already pleaded guilty in the bomb making case and is scheduled to be sentenced next month. According to court documents filed in Maryland’s federal court late Tuesday, Yevsukov’s father, Serafim, not only taught Patrick how to make the pipe bombs, but also bought the supplies for him.