Abstract: It is shown that in certain classes of finite groups, inner automorphisms are characterized by an extension property and also by a dual lifting property. This is a consequence of the fact that for any finite group $G$ and any prime $p$, there is a $p$-group $P$ and a semidirect product $H = GP$ such that $P$ is characteristic in $H$ and every automorphism of $H$ induces an inner automorphism on $H/P$.