Q: Is it legal to record person in their home committing a crime to later use as blackmail or proof in child custody case

A: No, it is not legal to secretly record someone in their own home without their consent in order to blackmail them or use the recording in a child custody case. This would be considered a serious violation of privacy and could potentially lead to criminal charges.

Some key points:

- In most jurisdictions, recording someone in their own home without their knowledge or permission is illegal. There are strict privacy laws protecting people from surreptitious recording in places where they have a reasonable expectation of privacy, like their home.

- Using a secret recording to blackmail someone or coerce them is illegal extortion, even if the recording shows them engaging in illegal activity. Blackmail is a crime.

- While documented evidence of criminal behavior by a parent could potentially be relevant in a child custody proceeding, secretly recording the other parent is not the proper way to obtain such evidence and the recordings would likely not be admissible in court. There are legal processes that should be followed.

- Installing hidden cameras or recording devices in someone else's home is a serious invasion of privacy and could lead to criminal charges like wiretapping, voyeurism, or stalking, depending on the jurisdiction and circumstances.

The proper course of action if one suspects criminal activity or child endangerment is to go through official legal channels, not to take matters into one's own hands through illegal secret recordings. Consult with police, child protective services, and family law attorneys about proper evidence gathering methods that comply with the law. Illegal recordings are not the answer and will likely only make the situation much worse for all involved.