Most books built around convictions of innocent defendants end with exoneration. In “The Injustice System,” the alleged innocent is still locked in a prison cell and might never emerge. Any well researched book about a suspected wrongful conviction is by definition shot through with dramatic tension; after all, if the wrong person is serving prison time, the actual murderer or rapist or robber might be at large, continuing to commit horrific crimes. The tension within the pages of “The Injustice System” is relentless.

Author Clive Stafford Smith is a former Atlanta lawyer (now based alternately in New Orleans and his native England) who earned a law degree in the United States so he could work on putting an end to the death penalty in the long run and save individual inmates from execution in the short run.

Driven more by principle than a won-loss record in court or a hefty salary, Stafford Smith is an unconventional professional who dives into high-stakes cases. His previous book, “Eight O’Clock Ferry to the Windward Side,” chronicles his experience representing prisoners at the U.S. prison at Guantanamo Bay, where alleged terrorists are detained without the usual safeguards that protect individuals from wrongful incarceration.

When he first met Krishna “Kris” Maharaj, the primary subject of “The Injustice System,” Stafford Smith was affiliated with the Southern Center for Human Rights in Atlanta and representing prisoners in capital cases. At the request of British diplomatic officials, he took on Maharaj’s case.

Police arrested Maharaj, a Trinidad businessman of Indian heritage, in 1986 for allegedly murdering former business partner Derrick Moo Young and the partner’s son, Duane. The double murder occurred inside the DuPont Plaza hotel in downtown Miami. Maharaj proclaimed his innocence and said he could prove it if given the opportunity. But police, prosecutors and jurors did not believe him. Sentenced to death, Maharaj was jailed in Florida State Prison. Maharaj hoped to find competent legal representation to handle a final appeal, most of his appellate routes already having been exhausted before Stafford Smith learned about the case.

Based on his own investigation, Stafford Smith alleges evidence was cooked by an overzealous homicide detective; prosecutors bent the principles of justice they are sworn to uphold; forensic examiners provided biased readings of evidence; witnesses committed perjury; a trial judge was less than devoted to evenhandedness; and appellate justices dismissed powerful new evidence suggesting Maharaj’s innocence.

Most upsetting of all to an avid defense lawyer such as Stafford Smith, he claims the defense lawyer hired by Maharaj for the trial was grossly incompetent. In truth, Stafford Smith worried the defense lawyer lost the trial intentionally because of threats aimed at his family by South American drug dealers, whom Stafford Smith suspected was involved in the murders.

As in so many alleged wrongful conviction cases — and in so many documented exonerations — it is puzzling to calculate how a dozen jurors all failed to find “reasonable doubt.” Stafford Smith wants to believe he can find a way to prove Maharaj’s innocence. The reality is, however, that Stafford Smith will likely go to his own death without winning freedom for his client. That knowledge is especially painful to Stafford Smith, because he believes his independent investigation has identified the actual killer of Moo Young and his son.