Jim Caviezel, before the shooting of the film, spent several days shadowing Tim Ballard and learning about Operation Underground Railroad's operations. He was able to go to Latin America and witness an operation led by Ballard himself.

Ballard founded O.U.R. after leaving the Government in order to combat the problem of sex slavery. He founded it to give him the ability to conduct operations that he was not able to at the government. He now acts as the CEO., which is conducting operations and saving children to this day all over the world, from Latin America to Middle East. Ballard estimates that O.U.R. saved the lives of 4,000 children.

Sound Of Freedom – The Real Life Fight to End Child Trafficking
Link : https://t.co/IR2ZhoEbo3?so...

Cast
Jim Caviezel as Tim Ballard
Mira Sorvino as Katherine Ballard
Bill Camp as Batman
Kurt Fuller as Frost
Gary Basaraba as Earl Buchanan
José Zúñiga as Roberto
Gerardo Taracena as El Alacrán
Scott Haze as Chris
Eduardo V