“Falsifying evidence” can describe different California offenses. Penal Code section 132 concerns knowingly offering a forged or fraudulently changed writing as genuine in a legal proceeding; section 134 concerns preparing false material for deceptive use in a proceeding; and section 141(a) covers specified wrongful acts involving physical matter, digital images, or video recordings when the required intent is present. An inaccurate record, an item that was moved, or an allegation that evidence was planted does not by itself establish any of these crimes. (Penal Code §§132, 134, 141.)

Compare the charged statutes

Possible charge Conduct and required state of mind Classification and key limit
Offering forged writing — §132 Knowingly offer a forged, fraudulently altered, or antedated book, paper, document, record, or other written instrument as genuine or true in a trial, proceeding, inquiry, or investigation authorized by law. Felony. The statute addresses offering the writing as evidence; making or possessing it without that offer is not automatically this offense.
Preparing matter for deceptive use — §134 Prepare a false or antedated book, paper, record, written instrument, or other matter or thing, intending it to be produced or allowed to be produced as genuine or true for a fraudulent or deceitful purpose in a law-authorized trial, proceeding, or inquiry. Felony. Actual presentation is not required by the statutory text, but creation alone without the required future-use intent is not enough.
Altering, planting, or moving specified material — §141(a) Knowingly, willfully, intentionally, and wrongfully alter, modify, plant, place, manufacture, conceal, or move physical matter, a digital image, or a video recording, with specific intent that someone be charged with a crime or that physical matter be wrongfully produced as genuine or true in a legal proceeding. Misdemeanor for the ordinary-person branch. The second intent clause refers to physical matter; it should not be expanded to all digital material.

Sections 141(b) and (c) set out separate felony provisions for peace officers and prosecutors, with different conduct and intent requirements. Those branches do not make every allegation of planted evidence a felony. Section 135 is different: it addresses willfully destroying, erasing, or concealing material known to be about to be produced as evidence, with intent to prevent the material or its content from being produced. A knowingly false crime report is another issue; for that distinct subject, see California’s false domestic-violence-report discussion. (Penal Code §§135, 141.)

If a case involves disputed evidence, preserve the original item and any versions or metadata. Note who created, changed, moved, or offered it, where it was meant to go, and the proceeding involved. Keep the actual charging document; the statute named there matters. The Law Offices of David S. Chesley can discuss a California criminal case at (800) 755-5174.