By Agence France-Presse The Saudi military student who killed three Americans at a US naval base in December had longstanding ties to Al-Qaeda and planned an attack before he arrived in the United States, US justice officials said Monday. The December 6, 2019 attack by Saudi Royal Air Force 2nd Lieutenant Mohammed Alshamrani involved years of planning, says the FBI (FBI/AFP/File / Handout / MANILA BULLETIN) The December 6 attack by Mohammed Alshamrani, a Royal Saudi Air Force flight student at the Naval Air Station Pensacola in Florida, "was actually the culmination of years of planning and preparation," said FBI Director Christopher Wray. Evidence discovered on an encrypted cell phone shows he was radicalized at least as far back as 2015, and had since been associating with "dangerous" operatives from the Yemen-based Al-Qaeda in the Arabian Peninsula (AQAP), Wray added. The FBI and Justice Department revealed their findings after a months-long effort to crack the encryption on Alshamrani's iPhone, which they said Apple refused to help with. US Attorney General Bill Barr accused Apple of putting its own financial interests ahead of the nation's. "If not for our FBI's ingenuity, some luck, and hours upon hours of time and resources, this information would have remained undiscovered," Barr said. "The bottom line: our national security cannot remain in the hands of big corporations who put dollars over lawful access and public safety. The time has come for a legislative solution," he said. Apple rejected suggestions that it did not cooperate in the investigation. But the company also said that creating a so-called "back door" into its phones for US law enforcement would make them vulnerable for a wide range of hackers. "There is no such thing as a back door just for the good guys, and the American people do not have to choose between weakening encryption and effective investigations," Apple said in a statement.