After a case is concluded, typically after direct appeal or the time to file appeal has passed, the clerk will send a notice out to the parties informing them of her intention to destroy exhibits. If there is good reason (e.g., further litigation expected), a party can request that the court maintain the exhibits for a longer period. In addition a party can request to have the exhibits released to them if the other side has no objection.
In CA you have 60 days to appeal a judgment. If you haven't done so the Court will issue the notice of intent to destroy trial exhibits. Ms. O'Connor may be right that you can get some of them back but don't expect to get your guns back if the case involved guns or contraband if the case involved drugs. The police are very reluctant to return certain kinds of property and even a Court order may not deter them from keeping it.
No, typically, evidence is not returned unless the case is over, and then, since the court doesn't have space to store every case's evidence, the clerks want your stuff out of there to make room for the next cases. So this is the time to claim your original papers and any physical evidence that you want to keep.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.