Corbett, who was at the Academy of Natural Sciences on Thursday night for a Chamber of Commerce gathering, left the stage without answering reporters' questions about Gibson.
Corbett's office later released a statement saying the governor was "surprised and concerned to learn about the allegations regarding my son-in-law Gerold Gibson. Susan and I continue to give our family our love and support."
Gibson is married to Corbett's daughter, Katherine, 33, who works as a deputy attorney general in Philadelphia.
Reached at her office, Katherine Gibson said she had "no idea" about the investigation of her husband.
"We're actually separated," she said, declining to comment further.
Before joining the A.G.'s office, Katherine Gibson worked for several years as an assistant district attorney in Philadelphia. The couple have been married since May 14, 2010, and have a 1-year-old son.
A commanding officer alerted the police commissioner's office last spring that there were strong suspicions that Gibson sporadically took money and other items during drug investigations, several sources close to the case told the Daily News.
Within a few days, Commissioner Charles Ramsey met with Internal Affairs supervisors, high-ranking police officers and two federal agents to discuss how to handle the Gibson investigation.
On Thursday, investigators set up a sting. In the early afternoon, Gibson was asked to drive a car that had been confiscated during a drug raid to narcotics headquarters in the East Division.
Investigators had planted money in several spots inside the car, which also was equipped with surveillance. The cash was marked with a chemical that glows in the dark but cannot be seen by the naked eye in daylight.
Gibson allegedly pocketed about $140, sources said.
When investigators took Gibson in for questioning, they put him in a room and turned out the lights, a source said.
"He lit up like a Christmas tree," a source close to the case said.
Gibson likely will not face federal charges because the money allegedly taken was not a large amount, law-enforcement sources said. The District Attorney's Office was notified of the investigation Thursday afternoon.
Former Gov. Ed Rendell said that word of the Gibson investigation spread quickly in political circles.
"As a parent, I feel sorry for the governor," Rendell said. "But regardless of the outcome, it won't have an impact on him politically. People don't hold elected officials responsible for the actions of their relatives."
Gibson is a member of the elite Narcotics Field Unit, from which several officers have been under investigation for misconduct in recent years.
An FBI-led task force was launched in 2009 when the Daily News began running a series of articles focusing on alleged misdeeds of one narcotics squad. The series, "Tainted Justice," went on to win the Pulitzer Prize for investigative reporting.
One cop allegedly lied on search-warrant applications, and when squad members raided bodegas and smoke shops, they allegedly took cash and merchandise after they cut wires to the surveillance cameras. And three women alleged that one member of the squad fondled, groped or sexually violated them during raids.
Six members of another squad were transferred in December after the D.A.'s office said that the officers no longer would be called to testify in drug cases.
Federal lawsuits and citizen complaints to Internal Affairs accuse these officers of theft, physical abuse and planting and/or fabricating evidence.
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