Denise Richards may testify against ex-hubby Charlie Sheen

Will Charlie Sheen's ex-wife, Denise Richards, be asked to testify about alleged 2005 violence that mirrors his current wife Brooke Mueller's allegations on Dec. 25, 2009?

Seems the D.A. is interested in a declaration Denise signed when she obtained a restraining order against the "Two and a Half Men" star, according to TMZ.