TJ Watt/Oscilloscope

Still from If a Tree Falls, directed by Marshall Curry.

There's an old maxim: one person's terrorist is another's freedom fighter. That's certainly the case with the radical environmental group, the Earth Liberation Front. ELF was responsible for a series of bombings against businesses the activists thought were ruining the environment. No one was hurt, but property owners sustained millions of dollars in damage. The federal government labeled ELF a terrorist group and went after its members, including a young man named Daniel McGowan. A recent documentary on ELF explores the prosecution of McGowan, who was facing life in prison. 'If a Tree Falls' director Marshall Curry joins us.

If a Tree Falls airs Tuesday on PBS. Listings here.

Trailer for If a Tree Falls: