‘At the Death House Door,” which premieres Thursday at 9 p.m. on IFC, is a somber, moving, and slightly manipulative examination of the Texas death penalty system. It is also a riveting character study of Pastor Carroll Pickett, a sturdily built, white-haired man who, as a prison chaplain, reluctantly, stoically, and at times even heroically presided over 95 executions at the “Walls” prison in Huntsville, Texas, until he could stomach no more and quit after 13 years’ service in 1995.

Mr. Pickett’s decision to retire came six years after the execution of Carlos De Luna, a 27-year-old petty criminal who was the first American to be put to death by lethal injection, and of whose innocence Mr. Pickett was and is convinced. That conviction, as well as his experiences ministering not only to De Luna but to 94 other condemned men during their final hours, led him to his current position as a restrained but passionate advocate against the death penalty, on the grounds that it is “cruel and unusual punishment,” although, it has to be said, it is not all that unusual in Texas.

Co-directed and produced by Steve James and Peter Gilbert, the men behind “Hoop Dreams,” the critically acclaimed 1994 basketball documentary, “At the Death House Door” might have proved unwieldy in less skilled hands, since it is really two movies in one. At its heart is its meditative portrait of Mr. Pickett, his life, his family, and his wrenchingly conflicted thoughts about his time at Huntsville, and whether — as someone else puts it — he was serving God or the state of Texas in his effort to be a “friend” to those on Death Row. This is brilliantly done, and Mr. Pickett’s dilemma is all the more affecting for his soft-spoken, modest, and emotionally frugal demeanor.

Intersecting and at times overwhelming this central narrative comes the much more exhortatory account of how De Luna, only recently out of jail, was arrested for killing a gas station attendant in Corpus Christi in 1983. According to Steve Mills and Maury Possley, reporters for the Chicago Tribune who have written about the case at length and are featured in the documentary, it is a crime he almost certainly did not commit.

The problem with the film is that while the men from the Tribune are investigative reporters, marshalling facts and logic, De Luna’s death, and particularly its traumatic effect on his sister, Rosa Rhoton, is milked a little too freely for emotional effect by Messrs. James and Gilbert without any corresponding investigative work of their own. While it’s true that De Luna’s execution is the one that haunted Mr. Pickett the most (making matters worse, the lethal injection was botched, and it took several minutes for De Luna to die), repeated close-ups of his face, or for that matter of a smiling Karla Faye Tucker (the first woman to be executed in America since the Civil War, on the orders of Governor George W. Bush in 1995), aren’t a substitute for intellectual argument about the pros and cons of capital punishment.

Most of the Western world has abolished the death penalty, and a case like De Luna’s can make for an almost impregnable argument against it, and that’s without even debating a government’s right to take away human life. Nonetheless, there is another side to the debate, and the film fails to give it its due. For instance, in his memoir, “Experience,” Martin Amis recounts a conversation he had in a Boston coffee shop with Saul Bellow around the time of Karla Faye Tucker’s execution in 1998. Mr. Amis was castigating Americans for being so indifferent to the barbarity of the executions taking place in their midst, only to notice that the great Nobel laureate sitting across from him didn’t appear to be all that sympathetic to his abolitionist stance. Somewhat astonished, he inquired if Bellow actually supported the death penalty.

“Well,” Bellow replied. “Look at … Eichmann. What are you supposed to do with a son of a bitch like that?”

It’s a good question. Armed with a gold mine of a protagonist and tasteful, mournful music, “At the Death House Door” can seem a little glib in its conflation of a gross miscarriage of justice with the death penalty per se (even if the two are morally bound at the hip), and is not always as forthcoming as it might be about what some of the people on death row actually did to earn their place there.

One of the most horrifying things I’ve ever seen on television was the sight of the German cannibal, Armin Meiwes, who ate someone after meeting him over the Internet, genially shaking hands with his lawyer in the courtroom. There are times (very few, admittedly, but no less important for that) when it almost seems more humane to kill than not. In fact, when Mr. Pickett’s daughter asks him what he would advocate if she were sadistically raped and then murdered (the infamous Michael Dukakis question), he replies that a lifetime of solitary confinement, with only one hour outside the cell a day, would actually be a more cruel fate for the perpetrator than putting him to death. Perhaps.

Mr. Pickett, who recorded the details of each of the executions he presided over on 95 separate cassettes, is a pensive, conscientious man who became a prison chaplain without wanting to be, only to discover that part of his job would be comforting those about to die. If one suspects that his abolitionist position is in part a form of therapy for all he has been through, it’s hard to begrudge him it.

However, that doesn’t alter the fact that there is something just a touch too smooth about this impressive and at times deeply poignant documentary.