Legal Question in Criminal Law in Michigan

Yes. It is legal if one party consents to the conversation. Ie- the taper knows it is being recorded. Tim Klisz. Kliszlaw.com

Some states are "one-party" states, others are "two-party states". In two-party states, every one in the conversation needs to know of and consent to the recording. Michigan is in the first group, so only one participant in a conversation needs to know that it is being recorded and consents to the recording. The federal law is "two-party", so it's possible that a person in Michigan, taping a phone call with a person in California, could comply with state law but violate federal law. Also, Michigan's "participant monitoring" statute discussed here would make it illegal for a spouse to set up a system to record all phone calls on the house phone to see if there's evidence the other spouse is having an affair, or even for a parent to monitor their children's phone conversations (that the parent is not an overt participant in). I'm not saying that these situations would be prosecuted, just that they could be prosecuted.