She said his own rape likely played a role in the rapes and murders of multiple women for which he is currently accused.
The Associated Press reports the letter was written to a Fairfax judge, and alleged Matthew was sexually assaulted by at least three people when he was young.
Matthew faces a capital murder charge for the murder of University of Virginia student Hannah Graham in 2014. He was recently charged with the murder of Virginia Tech student Morgan Harrington, who disappeared from Charlottesville in 2009.
Matthew is scheduled to appear in an Albemarle County court Wednesday, for a motions hearing in the Harrington case.
On Friday, Matthew will be sentenced for his conviction in the Fairfax rape case, from 2005. The DNA collected in connection with Harrington’s death matched DNA evidence from the 2005 case.