Final answer:
The information provided does not directly answer how many of the 162,000 federal cases were not indicted in 2012. To determine the number of non-indictments, access to detailed federal case statistics for that year is necessary.
Step-by-step explanation:
The question regarding the number of cases not indicted out of 162,000 federal cases in 2012 cannot be answered directly with the given information. The provided indictment numbers and counts of guilty versus not guilty do not directly offer a statistic on indictments.
Typically, an indictment is a formal accusation initiating a criminal case, but not all cases lead to an indictment as they might be resolved earlier through plea bargains, dismissed, or handled in other ways.
To find the exact number of cases not indicted, one would need access to comprehensive federal case statistics for that year, detailing all dispositions, including those cases not resulting in indictment.