"Common sense" is what people appeal to when they don't have real evidence.
If Oswald had gone to trial for the murder of J.D. Tippit, common sense matters.
Regarding the evidence that exists and "evidence" that does not exist, juries are required to make reasonable inferences. A judge will advise a jury about what is and what is not reasonable. Common sense must prevail in respect to the evidence (which is overwhelming in the case of Tippit).
The US Law Dictionary defines 'common sense' as:
'Sound practical judgment; that degree of intelligence and reason, as exercised upon the relations of persons and things and the ordinary affairs of life, which is possessed by the generality of mankind, and which would suffice to direct the conduct and actions of the individual in a manner to agree with the behavior of ordinary persons.'