Waco (FOX 44/KWKT) — Four people are facing federal drug charges in connection with the death of Cameron Mann Chamberlain, the spouse of a soldier at Fort Cavazos. They are accused of being involved with fentanyl trafficking.

Chamberlain was married to Spc. Craig Chamberlain, who disappeared in March of this year. Mann asked for the public’s help to find him in May and he returned soon after her death.

Court documents show Copperas Cove Police officers worked with the Army Criminal Investigation Division to arrest 36-year-old Julio Bonilla-Tirado of Copperas Cove on September 14th. Gilberto Hernandez-Marin, Juan Cabral, and Adxel Romero-Flores were all arrested in Puerto Rico.

The four face charges of conspiracy to possess with intent to distribute at least 400 grams of fentanyl resulting in death and unlawful communications. If convicted, each defendant faces a penalty of 20 years to life in prison.

A federal district court judge will determine any sentence after considering the U.S. Sentencing Guidelines and other statutory factors.

Army CID is investigating the case with the help of the DEA, Homeland Security, Killeen Police, Copperas Cove Police, and many more.

This is a developing situation and FOX 44 News will bring you more information as it becomes available.