Divorce is an emotional time whether or not the split is amicable. These emotions can cause people to make choices they would otherwise never make, such a looking through their former spouses computer or cell phone. Whether the clandestine act is out of sheer curiosity or for a specific purpose, a great deal of information can be learned about a person by looking through their cell phone or computer. This may include bank statements for accounts that were previously unknown, emails, dating profiles, messages to friends about the marriage or a possible affair.
In more extreme cases, one party may put tracking software on the other party's computer, such as key logger software, to track every move the other party makes on their computer. This could lead to very damaging evidence that would be very helpful in a divorce case.
The problem is you probably cannot use any of the information you obtained, and could end up facing a lawsuit by your former spouse and/or jail time for violation of several California laws as well as Federal laws.
In California illegally obtained evidence cannot be admitted as evidence in a court proceeding if the manner in which the evidence was obtained violates the Penal Code. This includes tape recording a conversation without the other party's consent, eavesdropping on a private conversation, or accessing/recording the contents of another person's electronic device (computer, phone, etc.) without their permission.
There are two exceptions to this rule:
1. Illegally obtained evidence can be admitted if it comes from another source, or would have been or was discovered independently.
This means if you discovered the other spouse had a previously undisclosed bank account because you broke into their computer and found emails from the bank, but subsequently learned about the secret account when you found a bank statement on the kitchen counter, you could use the evidence.
2. The individual from whom the evidence was illegally obtained waives the right.
This would generally include the other party providing the evidence by way of a response to discovery or in testimony.
There are other ways the evidence can be used, but not admitted at trial or hearing. For example, if the evidence is used to refresh a witnesses' recollection of certain events. This is because the evidence being used to refresh the witness's' recollection is not being introduced; it is simply an aid to the witness to recall an event he/she is testifying about.
Another way illegally obtained evidence can be used is to impeach a witness's credibility. This means, if the other party testifies that they have no accounts with ABC Bank and Trust, you can use the illegally obtained evidence to prove they do have accounts at ABC Bank and Trust.
A note of caution...just because you may be able to use illegally obtained evidence in your family law matter does not mean the other party cannot file a law suit against you for illegally obtaining the evidence in the first place. Moreover, you may still be subject to an indictment for violations of the penal code for any actions taken to obtain evidence from another party illegally. Remember, illegally obtained information is by definition "obtained illegally."