Sao Paulo, Brazil ? Two U.S. pilots were charged Friday by Brazilian police in connection with a collision over the Amazon jungle that left 154 people dead, authorities said. It was the worst aviation accident in the country’s history.

One of the pilots’ attorneys, former Justice Minister Jose Carlos Dias, called the accusation biased and said police were simply “looking for someone to blame for the crime.”

If convicted of exposing an aircraft to danger, the men could face up to 12 years in prison apiece, Brazilian federal police said. Dias said the maximum sentence would fall to four years each if the factors leading to the collision were deemed unintentional.

Joseph Lepore, 42, of Bay Shore, N.Y., and Jan Paladino, 34, of Westhampton Beach, N.Y., were questioned by police for six hours Friday and then allowed to pick up their passports and leave the country. They went directly to the airport and took a charter jet to the U.S. They were expected to arrive at an airport in Long Island today.

The pilots signed a legal document promising to return to Brazil for their trial or if required by local authorities. An extradition treaty between Brazil and the U.S. allows both countries to request the return of individuals if the offense committed is considered a crime by both nations.

Lepore and Paladino were piloting a Brazilian-made Legacy executive jet on Sept. 29 when it collided with a Gol Airlines Boeing 737-800 heading south over the Amazon jungle. All 154 people aboard the Gol flight were killed, while the Legacy landed safely with all seven people aboard unharmed.

Police filed the accusation because “elements and evidence in the investigation indicated a lack of caution necessary and expected from pilots during flight,” police said in a statement.