A former American immigration officer convicted of exchanging visas for bribes with Cambodian immigrants was sentenced to more than four years in prison on Monday night in California.

From 2005 until 2008, Billy Louis Nelms Sr, 54, worked as a federal officer in a Fraud Detection and National Security unit in Santa Ana, California, during which time he accepted bribes of up to $5,000 in cash from Cambodians looking for permanent legal status in the United States, according to the indictment. Nelms instead provided temporary legal status to an undisclosed number of Cambodian immigrants, a statement from the US Attorney’s Office said.

In August, Nelms was found guilty of conspiracy, accepting bribes and tampering with a witness. His wife, Sokhon Nelms, 60, was also found guilty of conspiracy and witness tampering, including, according to the statement, telling a witness to speak to no one. She is awaiting sentencing in November.