“Mistake” as a Defense to Perjury
Under Penal Code 118, a person commits perjury in California when he willfully gives false testimony while under oath. This usually happens at court proceedings or depositions, but it can also occur in affidavits or any document that’s signed under oath.
To count as perjury, the false statement must be “willful.” This means, in effect, that the perjurer knew the statement to be false but intended it to be taken as true. There must have been an intent to deceive.
A person who mistakenly makes a false statement is not guilty of perjury. For example, suppose Jane testifies as an alibi witness in Paul’s murder trial. She testifies that she saw Paul in Berkeley at the time of the murder, when the murder took place in San Diego. It turns out Jane is mistaken. Surveillance tapes, other witnesses and a confession all put Paul at the scene of the murder.
Jane’s testimony was false. But it wasn’t willfully false. So she didn’t commit perjury. Now it’s possible she could still get charged with perjury, if the prosecutor believed she was deliberately trying to deceive the jury. At trial the issue would be whether she was honestly mistaken, or telling a lie. Unless the latter could be proven beyond a reasonable doubt, Jane would be entitled to an acquittal.
