Is a search warrant legal when it is not notarized?

Typically, In Michigan a search warrant does not have to necessarily be notarized, it simply has to state the conditions and areas to be searched, and the facts surrounding why the search is necessary. It then has to be presented to and signed by a sitting judge. Once signed and sworn to by the issuing officer, the warrant becomes valid and does not need to be notarized, although sometimes the judge may have the court's seal attached to it. Check with a local criminal defense attorney in your area to determine the specifics of what is and what is not considered to be a valid search warrant in your state.