The movie is about a 17-year-old Mexico City boy trying to find and rescue his 13-year-old sister who was abducted by sex traffickers intent on selling her as a slave in the United States.
Kline plays the Texas cop who aids the boy in his search.
"I read the New York Times Magazine piece that Peter Landesman had written, but then reading the script and doing the research I did, I was appalled and horrified and made much more aware of the enormity of this global (crisis,)" Kline told UPI in New York.
Kline said he thinks corrupt officials complicit in getting victims over international borders are a main reason this inhumane practice is able to continue, but he also noted there is a lack of clear laws that address human trafficking.
"(New York) Gov. (Eliot) Spitzer (recently) helped push through, finally, new laws that were not on the books before. In New York State, there were no strict laws against sex trafficking and we are only the 28th or 29th state to actually have that."