Here is a link to Florida's standard jury instructions for criminal cases. The weighing of evidence begins at Section 2.04
http://www.flcourts18.org/PDF/criminal.pdf
2.04 WEIGHING THE EVIDENCE
It is up to you to decide what evidence is reliable. You
should use your common sense in deciding which is the best
evidence, and which evidence should not be relied upon in
considering your verdict.
You may find some of the evidence not
reliable, or less reliable than other evidence.
You should consider how the witnesses acted, as well as
what they said. Some things you should consider are:
1. Did the witness seem to have an opportunity to
see and know the things about which the witness
testified?
2. Did the witness seem to have an accurate
memory?
3. Was the witness honest and straightforward in
answering the attorneys' questions?
4. Did the witness have some interest in how the
case should be decided?
5. Does the witness' testimony agree with the other
testimony and other evidence in the case?
The instructions covered under paragraphs numbered six
through ten, inclusive, are not common to all cases. These
numbered paragraphs should be included only as required by the
evidence.
6. Has the witness been offered or received any
money, preferred treatment or other benefit in
order to get the witness to testify?
7. Had any pressure or threat been used against the
witness that affected the truth of the witness'
testimony?
8. Did the witness at some other time make a
statement that is inconsistent with the testimony
[he] [she] gave in court?
Note to
Judge:
The court also may wish to give as part of this instruction
the instructions covered under 2.04(a) and (b), concerning expert
witnesses and accomplices. If so, the Committee recommends that
they be given as additional numbered paragraphs, which would
precede the last two unnumbered paragraphs of this instruction.
9. Was it proved that the witness had been
convicted of a crime?
10. Was it proved that the general reputation of the
witness for telling the truth and being honest
was bad?
You may rely upon your own conclusion about the
witness.
A juror may believe or disbelieve all or any part of the
evidence or the testimony of any witness.