One very useful technique in modern investigation is to find out what the defendant was searching for on her computer about the time of the crime.  Unfortunately, the prosecutors in the Casey Anthony case did not have important information, Tony Pipitone reports for WKMG in Orlando:

Consider what they appear to show happening online the afternoon of Monday, June 16, 2008, the day Caylee died:

• At 2:49 p.m., after George Anthony said he had left for work and while Casey Anthony's cellphone is pinging a tower nearest the home, the Anthony family's desktop computer is activated by someone using a password-protected account Casey Anthony used;

• At 2:51 p.m., on a browser primarily Casey Anthony used, a Google search for the term "fool-proof suffocation," misspelling the last word as "suffication";

• Five seconds later, the user clicks on an article that criticizes pro-suicide websites that include advice on "foolproof" ways to die. "Poison yourself and then follow it up with suffocation" by placing "a plastic bag over the head," the writer quotes others as advising;
•  At 2:52 p.m., the browser records activity on MySpace, a website Casey Anthony used frequently and George Anthony did not.

Any why didn't the prosecutors know any of this?  The investigators only checked the Internet Explorer history.  Casey Anthony had switched to Firefox.  And now she is living the "bella vita."  Caylee is not.