In Benedetto et al. (2025, J. Lond. Math. Soc., 112, Article no. e70257), we provided an explicit description of the arboreal Galois group of the postcritically finite polynomial $f(z) = z<^>2 +c$ in the special case when the critical point $0$ is periodic under the action of $f(z)$ . In the current article, we complete the picture for all postcritically finite polynomials by addressing the cases when $0$ is strictly preperiodic for the polynomial $f(z)$ .