Criticism of the video game industry and violent video games has resurfaced since last week’s shooting at an elementary school in Newtown, Conn. Several politicians, including John Hickenlooper (D), the governor of Colorado , and Sen. Joseph Lieberman (I-Conn.), have mentioned a link between violent games and aggression. On Wednesday, Sen. Jay Rockefeller (D-W.Va.) introduced a bill that calls for the National Academy of Sciences to examine the effect of violent video games as compared to other mediums.

“Major corporations, including the video game industry, make billions on marketing and selling violent content to children,” Rockefeller said in a statement. “They have a responsibility to protect our children. If they do not, you can count on the Congress to take a more aggressive role.”

In a statement late Wednesday, the Entertainment Software Association extended its “prayers and condolences” to the community of Newtown, but asked that any study take into account research that shows little link between video game violence and real-life violence.

“The Entertainment Software Association, and the entire industry it represents, mourns the tragedy at Sandy Hook Elementary School. Our heartfelt prayers and condolences go out to the families who lost loved ones, and to the entire community of Newtown,” the statement said. “The search for meaningful solutions must consider the broad range of actual factors that may have contributed to this tragedy. Any such study needs to include the years of extensive research that has shown no connection between entertainment and real-life violence.”

There have been some studies that show violent video games have some connection to higher levels of aggression, but not to real-life violent behavior. Last year, the Supreme Court used that argument as it struck down a California law that made it a crime to sell violent games to minors — adding that games were “as much entitled to the protection of free speech as the best of literature.”

Rockefeller said in his statement that recent court decisions show some people “do not get it.” He also called on the Federal Trade Commission to expand its work in setting ratings, and for the Federal Communications Commission to examine the impact of violent programming on children.

The Associated Press reported Wednesday that there have been multiple, as-yet-unconfirmed reports that Newtown shooter Adam Lanza, who killed his mother and 26 students and teachers on Friday morning, played a range of violent and non-violent games. Law enforcement officials, the report said, have not cited his reported interest in games as a possible motive for the attack.

The report also said that some in the gaming community have called for a digital “Day of Cease-Fire for Online Shooters” set for one week after the massacre out of respect for the dead.