He said he wanted to see how well federal laws protect children and to ensure that provisions for reporting suspected cases are in place.
Pennsylvania is not one of the 18 states that require all adults to report suspected child abuse.
The request results from the state investigation into Jerry Sandusky, a former assistant football coach who is charged with abusing eight children over a 15-year period.
Also charged were a pair of Penn State administration officials — then-athletic director Tim Curley and former senior vice president Gary Schultz. They are accused of not reporting alleged abuse on the campus to law enforcement and with lying to a grand jury.
All three men have said they are innocent.
"The serious nature of these allegations and the evidence on the public record of failure to report by individuals at Penn State warrants an immediate review of the relationship between federal and state reporting requirements on child abuse and neglect" Casey, a Democrat, wrote.
Justine Sessions, a spokeswoman for the Senate Committee on Health, Education, Labor and Pensions said it was "closely monitoring this situation and the ongoing criminal and Department of Education investigations, and will take Sen. Casey's request under consideration."
Casey's request came one day after Sandusky, once considered Paterno's heir apparent, said he had showered with young boys and hugged them but called the allegedly criminal contact "horseplay."
Sandusky told NBC News' "Rock Center" on Monday night that he was not a pedophile but, in retrospect, should not have showered with the boys he's charged with sexually assaulting.
In an interview with Bob Costas, Sandusky proclaimed his innocence in the face of a series of startling allegations detailed in a grand jury report.
"I am innocent of those charges," Sandusky said. "... I could say that I have done some of those things. I have horsed around with kids. I have showered after workouts. I have hugged them, and I have touched their legs without intent of sexual contact."
The grand jury said some of the crimes happened at Penn State, where Sandusky had access to campus as an emeritus professor following his 1999 retirement as Paterno's top defensive assistant.
Asked whether he was sexually attracted to underage boys, Sandusky said "sexually attracted, no. I enjoy young people, I love to be around them, but, no, I'm not sexually attracted to young boys."
Asked if there was anything he had done wrong, Sandusky said, "I shouldn't have showered with those kids."
When pressed about how two people could claim to have witnessed Sandusky engaged in sexual contact with boys on two different occasions, Sandusky replied that "you'd have to ask" them.
The scandal has hit hard the community called Happy Valley, where "success with honor" is the motto. Paterno and University President Graham Spanier have lost their jobs. Curley and Schultz also have left their posts.
The interview with Costas was Sandusky's first public comment on the charges. He had previously maintained his innocence through his attorney, Joe Amendola.
"We anticipate we're going to have at least several of those kids come forward and say 'This never happened. This is me. This is the allegation. It never occurred,'" Amendola said on the NBC broadcast.
A spokesman for Pennsylvania Attorney General Linda Kelly declined to comment on the interview, citing the active investigation.
Amendola earlier told CNN that his client was just behaving like "a jock."
"Jerry Sandusky is a big overgrown kid," Amendola said. "He's a jock, and for anybody who's ever played sports, you get showers after you work out."
The Associated Press made several efforts to reach Sandusky by phone and through Amendola, but messages haven't been returned. The AP also knocked on Sandusky's door and left messages at least three times over the past week.
On Tuesday, neither Amendola nor did Sandusky returned messages left by the AP.
Wide receivers coach Mike McQueary told a grand jury that in March 2002 when he was a graduate assistant, he saw Sandusky sodomizing a boy about 10 years old in a shower at the Nittany Lions' practice center. McQueary did not go to police but instead told Paterno, Curley and Schultz, although it is unclear how detailed a description he gave. Schultz, in turn, notified Spanier.
Sandusky told NBC there was no sexual contact.
"We were showering and horsing around, and he actually turned all the showers on and was actually sliding across the floor, and we were, as I recall, possibly like snapping a towel — horseplay," he said.
Amendola accused the attorney general's office of having "thrown everything they can throw up against the wall." He said some of the allegations, such as putting a hand on a boy's knee, do not constitute criminal conduct and other cases include no direct complaint by the boy.
"They have other people who are saying they saw something, but they don't have actual people saying, 'This is what Jerry did to me,'" Amendola said. "We're working to find those people, and when the time comes, and if we are able to do that, we think this whole case will change dramatically."
When Sandusky retired in 1999, at just 55, he cited his desire to devote more time to The Second Mile, a charity he founded in 1977 to help at-risk kids. According to the grand jury report, however, Sandusky was a sexual predator who used the charity and his Penn State connections to prey on boys.