The family of Kaylee Goncalves is livid over the plea deal offered to accused murderer Bryan Kohberger … and now it appears they’re hoping the feds will step in.

Here’s the deal …. Kohberger will plead guilty to four counts of first-degree murder, but prosecutors will take the death penalty off the table and recommend life without the possibility of parole. But some families of the four victims say the plea deal is unacceptable — and unfair to them.

The Goncalves family is now asking supporters who are just as upset as they are over the major development to get loud … and send their criticisms to the United States Department of Justice.

Sharing a link to message the DOJ … the family said in a statement posted to social media they’re “seeking all the support we can gather” and they “kindly encourage you to use this link to voice your concerns.”

TMZ broke the story yesterday, the family was outraged over the plea deal … with the Goncalves family telling us … “The death penalty is merely an illusion in the criminal justice system. When available, it serves as a bargaining tool for the State, and when rarely applied, it’s never enforced due to a highly inefficient appellate process.”

Kaylee’s family says … “The notion that someone can plead guilty to a crime and still face years of appellate delays reveals a systemic failure. The Latah County Prosecutor’s Office’s treatment of our family during this process is something I wouldn’t wish on anyone.”