Patricia Brown, 21, an inmate in the Federal Correctional Institution in Danbury, was charged Tuesday with attacking another inmate on May 4.
Brown, who is serving a 30-year sentence for murder, now faces new charges in prison. Brown was convicted of murder in 2009 in Minnesota. Details of the new assault were not available Tuesday.
The stabbing was made public by U.S. Attorney David Fein.
This case is being investigated by the Federal Bureau of Investigation and is being prosecuted by Assistant United States Attorney Neeraj N. Patel.