Law enforcement officers arrested a man linked to the fatal bombing at a Palm Springs, Calif., fertility clinic last month.

Daniel Park was taken into custody Tuesday at New York’s John F. Kennedy Airport after being extradited from Poland, where he fled to after the May attack, according to The Associated Press. Authorities say he’s spent years collecting ammonium nitrate to create self-made incendiary devices. 

Investigators said Park supplied Guy Edward Bartkus with the explosives that detonated at the clinic. Police said he shipped Bartkus 180 pounds of ammonium nitrate in January in addition to a separate package with 90 pounds of the chemical ahead of the fertility center strike.

The two reportedly met online in a chatroom that promoted anti-life rhetoric in opposition to population growth.

Bartkus was killed by the bombing, but police haven’t said whether or not his death was intentional, AP reported.

Park made his first federal court appearance Wednesday to answer for the crime.