Babylon 5, book 4 : Clark's Law
Jim Mortimore1996

Death Before Dishonor
The Tuchanq, a newly discovered humanoid species, can be an important ally for the Earth Alliance commanded by President Clark. So Captain John Sheridan welcomes their ambassadors to Babylon 5, not knowing that among them is D'Arc - a mass murderer on the run hoping to escape into the unsuspecting worlds of the galaxy....
Clark's Law
But the unforgiving rules of space have a different fate in store for D'Arc. A terrifying accident wipes away D'Arc's identity and his evil... leaving behind a loving, innocent being with a child's mind - a being that must die because President Clark, a leader with his own secret agenda, orders his immediate execution. Now, as Babylon 5 physician Dr. Stephen Franklin begs Sheridan to defy Clark's law, the captain faces the greatest test of his command - and a far greater test of his manhood, which may end his career in shame or become a shining reminder of what being human truly means...