Governor Tom Corbett ceremonially signed legislation Tuesday that will permit expert testimony in court regarding sexual assault victims.

House Bill 1264, sponsored by Rep. Cherelle Parker (D-Philadelphia), received unanimous support in the General Assembly and was officially signed by the governor on June 29. It takes effect on Aug. 28.

“We need to acknowledge and understand the unique dynamics of this sort of crime,’’ Corbett said. “This is a complex area with many shades of gray that require someone to explain to jurors why things unfolded the way they did.’’

The new law will allow expert witnesses to testify about a victim’s response and behavior during and after the sexual assault. Criminal justice advocates argue that expert testimony is necessary to provide jurors with the proper context in which to evaluate a victim’s behavior.

“The law needs truth, but it also needs context,’’ Corbett said. “This bill helps us in the search for justice.’’

Corbett signed the bill in a ceremony at the Harrisburg YWCA’s Violence Intervention Prevention Program center.

Joining Corbett at the ceremony was Rep. Parker, Pennsylvania State Police Commissioner Frank Noonan, along with representatives of the Pennsylvania District Attorneys Association, the Pennsylvania Board of Probation and Parole, the Pennsylvania Coalition Against Rape, the Office of Victim Advocate, the Bucks County Child Advocacy Center and the Network of Victim Assistance.

Prior to this law’s enactment, Pennsylvania was the only state that did not allow expert testimony in sexual assault cases regarding victims’ behavior.