When is eavesdropping legal?
The exceptions to the rule for eavesdropping or for putting a recording device on a phone are if the case involves threats of violence. If somebody is a stalker and you are investigating a stalking case and they are making a lot of harrassing phone calls, then the court makes exceptions and allows you to record your conversation so that you can document those threats. That's pretty much the only exception, when there is physical harm that has been threatened and you are trying to gather evidence of that. You can't tap a phone for marital infidelity. You can tap your own phone. You can record your own phone but again, you would have to let people know that it was being recorded. You're in a two-party state in California, you can't just put a recording device on your phone and say I want to catch you doing it. It doesn't mean that you can't record the conversation if they are not making a threat. It means that you can record the conversation if you believe that sometime during the conversation they are going to threaten you bodily, even if they didn't. If you believed it was going to happen and it happened in the past and you are trying to be prepared, then the recording is admissible. But nobody can go and monitor somebody's phone call, whether it is cellular or cordless phone or cutting directly into the phone line, legally. It just can't be done without a court order.
