By choosing a case that centers on an alleged cover-up, they said, they accomplished two objectives: moving against Ms. Brooks, who after Mr. Murdoch and his son James has been the most visible and controversial figure in the saga; and doing so in a case that was likely to be easier to prosecute than later cases that go to the heart of the suspected newsroom wrongdoing.

The charges on Tuesday relate to cover-up activities suspected to have occurred in a two-week period last summer, involving six people, and issues that will be easier for prosecutors to put to a jury, the experts said. By contrast, the allegations of phone hacking involve as victims at least 800 politicians, celebrities, crime victims and others, and a lengthy roll call of editors, reporters and investigators at the two tabloids who may have been involved. Complex issues of “who said what to whom and when” are likely to come up in any phone-hacking trials, as well as a likely argument from the defense that legal red lines were crossed in pursuit of issues that were in the public interest.

The heightened scrutiny of the tabloid practices began last summer when it was disclosed that hacking at The News of the World included the cellphone of a 13-year-old London schoolgirl, Milly Dowler, whose messages had been intercepted after she was abducted and before her body was discovered. That prompted Rupert and James Murdoch to fly to London and close the 168-year-old tabloid. Ms. Brooks, a former editor of the paper, quickly resigned as chief executive of News International, the Murdoch newspaper subsidiary in Britain. She was arrested the first time shortly afterward.

The two Murdochs then went before Parliament to testify about the affair, denying any cover-up by News International or News Corporation, the New York-based media conglomerate controlled by the Murdoch family. But by then the scandal, revealing the widespread contacts and influence that the Murdochs and their aides had at the heart of government, had developed a strong political taint, and Rupert Murdoch bowed to the mounting scrutiny by withdrawing a $12 billion takeover bid for BSkyB, the country’s most lucrative satellite broadcasting network.

It was in the midst of those events — between July 6 and July 19, 2011 — prosecutors said on Tuesday, that Ms. Brooks, her husband and the four others, including her private assistant at News International, her chauffeur and a bodyguard, were engaged in concealing documents, computers, electronic devices and archive material from Scotland Yard investigators.