Jesse Matthew of Charlottesville is currently scheduled for trial June 8 in Fairfax on charges that he attacked a woman in 2005.
The Fairfax trial has already been delayed once, but his public defender said Monday in court papers that she needs a second continuance.
Defense lawyer Dawn Butorac says she needs more time to investigate roughly 40 people identified in the police file as possible suspects over the years.
She also questioned whether the victim in the case will be able to identify Matthew as her attacker. Authorities say they have DNA evidence implicating Matthew.
Matthew is also charged with killing student Hannah Graham last year.
Suspect in Hannah Graham's death faces capital murder charge
Jesse Matthew sex assault trial in Fairfax County scheduled for June 8
Jesse Matthew Jr. charged with 1st-degree murder of Hannah Graham
Police seek person of interest seen with missing U.Va. student Hannah Graham
Mother of girl found murdered 5 years ago shares thoughts about disappearance of Hannah Graham