Chief Judge Belvin Perry made his ruling against Casey Anthony at a hearing Tuesday in Orlando.
The judge says Anthony's attorneys failed to prove prosecutors had a gender bias in seeking the death penalty against the Florida mother charged with killing her daughter, Caylee, in 2008.
An expert testified earlier that a mother who is perceived as "deviant" by a jury faces a difficult time defending herself against criminal charges.
Anthony has pleaded not guilty to murdering Caylee and said a baby sitter kidnapped the toddler. Her trial is scheduled to start in May 2011.
