Tag Archives: Detectives

Logical Gal and the bias against circumstantial evidence

12 May

circumstantial evidence and cat

Ask 9 out of 10 passers-by and they will most likely maintain that circumstantial evidence is weak.

And maybe one piece is, but I have been learning that there is POWER in the cumulative effect of multiple pieces of circumstantial evidence.

My tutor is a cold-case detective, J. Warner Wallace.  The only cases he works are cold murder cases that date back 10 to 30 years.  There is no date beyond which one cannot be tried for murder in the state of California.  A cold case is one that is old, unresolved and left untouched, gathering dust until someone decides to re-open it.

Detective Wallace recounts in his book about the ultimate cold case, the murder of Jesus Christ, Link to the book available at Amazon, how he has to instruct jurors on the 2 kinds of evidence.  Most Americans have no idea that one can convict a suspect of murder on the basis of circumstantial evidence alone!  But you need a lot of it.

Cold Case Chr - the book


Here is a brief primer: There is direct evidence and indirect evidence.

  • Direct is when you have Bob testify that he saw Frank stab the victim
  • Indirect is when you see a bloody knife in Frank’s car, plus blood on Frank’s pants, and you hear Frank threaten the deceased victim.  A

Inferences drawn from multiple pieces of indirect or circumstantial evidence  (think 20-30) can add up to a powerful case against a suspect.  In fact Wallace himself says his ONLY convictions have been in circumstantial cases.

The standard for the burden of proof in such criminal cases is ‘beyond a reasonable doubt‘.

Beyond a reasonable doubt

Wait a minute!  Think about what that phrase actually means – ‘beyond a reasonable doubt’.

In order for your doubt to be valid, you have to have a REASON such as:

  • ” I don’t think Frank could have stabbed the victim because the defense showed us a transcribed interview with a restaurant waitress and some colleagues and his ex-wife.  It seems as though Frank was at this very same ex-wife’s birthday party along with his former colleagues at IHOP at the time the victim is purported to have died (as determined by the autopsy)”

But the degree of proof the prosecution must provide is NOT beyond ANY shadow of a doubt.  Doubt and uncertainty are woven into life.  Where does anyone ever  have 100 % certainty?  The confidence the jurors must feel must be such that they can come up with no reasons to infer otherwise than that the suspect committed the murder.

So the next time you hear someone denigrate circumstantial evidence, “Oh, that’s just circumstantial!”, push back gently. Ask: “What’s wrong with circumstantial evidence?”  They probably won’t know how to answer.  Most people tend to parrot, unthinkingly, what they have picked up, floating in the air!

Question:  what beliefs have you absorbed without examining them? 

Logical Gal and the difference between objective terms and subjective values

4 Nov

Last time I wrote (post dated 1 Nov 2013),

I asserted that terms were by nature objective since they are descriptive of what is.

One of the laws of the universe (no human made this up) is called the Law of Identity.  An apple IS an apple.  All the attributes on the left of the IS add up perfectly to what is on the right side.   Add or subtract one of the attributes and you no longer have an apple.

I asserted that the definition of TRUTH is straightforward – It is that which corresponds to reality.

So where do values and opinions come in to play?  Can they be subjective?

Value statements depend on the presuppositions behind them.  Presuppositions are the assumptions we make that are often hidden.  But they totally influence our conclusions, our values!

Change the presuppositions and you alter the sense of the conclusion. Presuppositions are sometimes unarticulated in a discussion.  When you have just a partial argument, it’s called an ‘enthymeme’ because the missing parts are implicit.  

“You’ll get fat!”   when fleshed out could be part of a syllogism that looks like this:

  • Eating chocolate 3x a day causes people to get fat – (Presupposition)
  • You’re eating chocolate 3 x a day – (Presupposition)
  • Therefore, you’ll get fat – (explicit enthymeme that showed up just as conclusion)

Getting fat is a fact, it’s truth.  What I mean is:  ‘adding a pound of fat to your body‘ is what might be corresponding to reality  But again, depending on one’s values, being fat is either a sign of ill health, or a sign of prosperity and beauty. (Think of Rubens’ artwork!)


The fact of adding fat is the truth – it’s objective.

But what it means is relative and subjective to the one creating the proposition.  In the conclusion above, the proposition being asserted is this:  You (subject) are doing something that will cause you to get fat. (predicate)

That proposition is either objectively TRUE or FALSE.

It’s subjective sense is, however, relative…..relative to the assumptions/presuppositions one holds.

Clear thinking requires the use of tools and the time to employ them.  Asking questions and parsing out terms from propositions is one tool.  Teasing out the implicit ideas behind the propositions is another.  Be a diligent detective.