Grassley not satisfied with Sercret Service clean up, presses for full investigations The Secret Service's efforts to improve the conduct of agents working abroad is not enough for GOP Sen. Chuck Grassley, who continues to call for an independent investigation and be on the party's most persistent members on the issue. The 10-point code was issued late Friday, about two weeks after at least one agent allegedly brought a prostitute back to his hotel room in Cartagena, Colombia - as a team of agents prepared for President Obama's arrival for an April 14-15 summit. "The new conduct rules are necessary to preventing more shenanigans from happening in the future," said Grassley, R-Iowa and ranking member of the Senate Judiciary Committee. A sheet of paper with new rules doesn't negate the previous actions. ... It remains necessary to hold the agency and the agents accountable, following a complete and independent investigation. The new rules include chaperones on some trips, no excessive drinking, no foreigners in hotel rooms and no visits to disreputable establishments. Grassley, whose committee has oversight of the Secret Service, has pressed for answers since the scandal unfolded and perhaps widened. He has been particularly skeptical about whether similar incidents occurred in years past and if White House officials also traveling ahead of the president were involved in the scandal, which allegedly included dozens of prostitutes. Twelve agents and 12 military personnel have been identified in the incident. Eight of the agents have been forced out, one had his security clearance revoked and the remaining three have been cleared. CNN, then other news gathering agencies late Friday identified the agent at the center of the scandal. Grassley said Friday the White House failed to response to a letter sent by the Democrat-led Senate committee giving administration officials 48 hours to response to 14 questions about whether staffers were involved in the scandal. Grassley said he also sent several e-mail to the White House as reminders of the impending deadline. The White House counsel Kathryn Ruemmler did an own investigation that absolved staffer of any involvement. But Grassley felt that investigation was not credible, given its lack of independence. Secret Service and other federal officials have said they have no evidence to support news reports about similar incidents in Buenos Aires, Moscow and San Salvador as far back as 2000. However, Grassley remains unconvinced. "This culture can't persist, not only for the reputation of the United States but also for the protection of the president," he said Friday on CBS's "This Morning." Grassley's remark came two days after Homeland Security Secretary Janet Napolitano told committee members an internal Secret Service investigation went back two-and-a-half years and found no similar complaints. She also said the investigation was being conducted under the guidance of the Office of the Inspector General. Grassley has instead called for the office to do its own investigation.