Can I use recorded telephone call and personal conversation in which my soon to be ex-wife, has made suiside threats on several occasions and threatened to take my 18 month old son from me. Would these recordings help me retain custody of my son?

I would first find out if your state allows you to record calls like that. In a lot of states, it is illegal to records someone without their consent, and those who do can be charged with a crime for doing so.

I think in the States as long as one person has knowledge of the recording, it's legal. If it wasn't legal for the recording, what is on it may still be taken into consideration since the talk of suicide would be a health risk to the child if the mother decided to take that life as well as her own. I'd talk to someone in Social Services, Department of Child Endangerment. Maybe they can help you out or point you in the right direction.

In Canada, I believe as long as one party of the conversation knows they are being recorded you could try it. If these conversations were between your wife and a third party it wouldn't be successful and the chance of recorded phone calls being admissable is slim anyways. Good luck.

It depends on the state. Some states exclude illegally obtained recordings from court. Some states allow the evidence, even thought it is a felony to make the recording.