The Indiana Supreme Court has ruled in Gilmette v. State that police do not need a warrant to search property already in their possession thanks to a lawful arrest, even if that search reveals evidence unrelated to the crime for which the person was arrested. Ruling here.
This isn’t too surprising. But it does serve as a useful reminder that once the police have your property in their custody (assuming they’ve gotten in properly and legally), then can absolutely search it, do lab tests, etc.