Engineered, non-naturally occurring, RNA-targeting Type V Cas polypeptides lacking collateral cleavage activity, compositions thereof, CRISPR-Cas systems thereof, packaging and delivery systems thereof, kits thereof, and methods of use thereof, for modifying target RNA. The Type V Cas polypeptide may be a Cas12 polypeptide, optionally a Cas12a2 polypeptide. The compositions may comprise the Type V Cas polypeptide and an engineered polypeptide comprising a tetratricopeptide repeat (TPR) domain, a DUF3800 domain and, optionally, a UvrD polypeptide and an additional TPR polypeptide. CRISPR-Cas systems may comprise the Type V Cas polypeptide, or a composition thereof, and one or more guide molecules.