Solvable normal subgroups of 2-knot groups

If X is an orientable, strongly minimal PD4-complex and pi(1)(X) has one end, then it has no nontrivial locally finite normal subgroup. Hence, if pi is a 2-knot group, then (a) if pi is virtually solvable, then either pi has two ends or p congruent to Phi, with presentation < a, t|ta = a(2)t >, or pi is torsion-free and polycyclic of Hirsch length 4 (b) either pi has two ends, or pi has one end and the center zeta pi is torsion-free, or pi has infinitely many ends and zeta pi is finite, and (c) the Hirsch-Plotkin radical root pi is nilpotent.