FORT LEONARD WOOD  • He was a rising star described as the "most respected chaplain in the Army."

Assigned to the elite Special Operations Command, Lt. Col. Keith A. Jackson accompanied some of the first military forces into Afghanistan and Iraq, returned repeatedly to the combat zones and earned two Bronze Stars. He seemed destined for the military's highest ranks.

Instead, last week, Jackson became the latest soldier to be convicted of sexually exploiting a child. Over a seven-month period Jackson, 46, a married father of two, used the Internet to send hundreds of obscenity-laced texts and about seven hours of graphic video of himself to what prosecutors said he believed to be a 14-year-old girl. In reality, it was a St. Charles County Sheriff's detective.

A Pentagon spokesman said problems with child pornography and child sexual exploitation were not widespread in the ranks. Still, the military has taken steps to address the issue, including offering training and blocking access from government computers to some sites.

A spokesman for the National Center for Missing and Exploited Children said that although the organization saw many cases involving military personnel, it had no data to suggest the crimes were a greater problem in the military than in any other segment of the population.

"The military is like the rest of society," said Ernie Allen, the center's president. "The problems of child pornography and child sexual exploitation have exploded in this country particularly with the advent of the Internet. It's certainly our view that the military is not immune."

Allen credited the military for its aggressive pursuit of such cases and noted that a Naval Criminal Investigative Service agent was assigned to work directly out of the center.

"We're pleased and impressed with the effort of the military to attack this problem," Allen said.

In 2011, the Army tried 40 soldiers for child pornography, with 37 convicted and three acquitted. In addition, 26 soldiers were court-martialed for charges related to indecent acts, liberties or language with a child under the age of 16, with 22 convicted and four acquitted.

The numbers don't include soldiers tried in civilian courts. Army officials say they don't track those numbers, which makes it difficult to determine how widespread the problem might be.

At Fort Leonard Wood, at least eight soldiers, a Marine and a civilian employee have been charged since December 2008 with either producing, possessing or distributing child pornography or indecent conduct with a child. A fort spokesman said the command and was doing everything possible to eliminate an act that "compromises everything that our soldiers and Army stand and fight for."

"We are committed to using all available tools, including aggressive investigation, the Uniform Code of Military Justice and prosecution of offenders in court to reduce these behaviors," said Tiffany Wood, deputy public affairs officer.

Jackson was not assigned to Fort Leonard Wood. He was charged there after investigators from the St. Charles County Cyber Crime Unit discovered him in an Internet chat room for Missourians. The unit, which was formed in 2001, has four forensic computer analysts and three investigators. It handled more than 320 cases in 2010.

A DARK SIDE

Jackson was arrested in May in Alexandria, Va., where he was living while taking part in a fellowship affiliated with the Army War College, a coveted training program for senior Army leaders. He spent 10 days in solitary confinement in a civilian jail before the Army took jurisdiction of the case and he was transferred to Fort Leonard Wood to await court-martial.

There is no hard and fast rule for whether a soldier arrested by civilian authorities will end up being tried in a military court. In Jackson's case, the Army approached St. Charles County authorities about taking custody of Jackson, a 21-year veteran.

"Our preference is for us to clean our own laundry," said Col. James Agar, Fort Leonard Wood staff judge advocate.

Jackson faced 20 charges and 47 years' confinement for his Internet exchanges with a person using the screen name strawb3rry_babi, whom he first came across in a Yahoo chat room in September 2010.

During his court-martial last week, prosecutors portrayed Jackson as having a dark side: a trusted man of the cloth who provided honorable service to his nation but who repeatedly sought out a young girl for sexual gratification.

"He is the wolf in sheep's clothing," said Capt. Robert Luyties, the military prosecutor. "The cloak has been removed ... and we can see what Col. Jackson is — a man who likes to masturbate to 14-year-old girls."

Jackson's attorney countered that he was an outstanding officer deep in the grips of alcohol abuse and crumbling from the relentless pressures of his job. Jackson testified that he never believed the person he was communicating with was a minor, pointing out that the terms of use agreement required chat room participants to be at least 18 years old and that the undercover detective's profile listed her age as 23.

"Just because she said she was 14, doesn't mean he believed she was 14," said Frank J. Spinner, Jackson's civilian attorney.

Jackson said that he was role playing when he participated in the exchanges, often blacked out from the liquor he had consumed and afterward had little or no recollection of most of what occurred, including the detective's twice saying she was 14.

Jackson, wearing his dress blue uniform with rows of ribbons spilling across his chest, testified about having lost 20 close friends in combat. On three occasions, men died in his arms. He told of accompanying the bodies of fallen comrades home, ministering to their grieving families, conducting their funeral services, then returning to the battle zone to repeat the process. The high tempo of operations meant little down time for Jackson, one of the command's few available chaplains. He said he routinely failed to take his earned leave.

In 2005, he said, he began to drink heavily to help him sleep and forget traumatic events. He said that he was able to keep his drinking secret from his family and colleagues and that his career continued to flourish.

When he moved to Virginia in August 2010 to take part in a fellowship at George Mason University, his wife remained home in Fayetteville, N.C. Alone, depressed, grief-stricken and wracked with guilt over the deaths of his friends, Jackson said, his drinking escalated. He said he would sometimes drink a quart or more of vodka in 20 minutes and wake the next day with no recollection of what he had done.

He said that it was during those drunks and "blackouts" that he engaged in the improper Internet behavior, but that he had no recollection of it.

"I am repulsed by it and ashamed by it," he said.

Prosecutors pointed out that despite claims of blacking out, Jackson was able to recall key details of some conversations, never appeared with a drink in the hours of recorded web camera chats and typed one-handed without misspellings. They said the undercover detective never presented herself as anything other than a 14-year-old.

After listening to testimony over two days, Col. Jeff Nance, the military judge, found Jackson guilty of 18 counts. The sentence was still to come. Prosecutors asked for two years' confinement.

A FRAYING FORCE

Jackson knew before the court-martial began that his Army career was over. He hoped to at least salvage his retirement and avoid having to register as a sex offender, which he said would make it almost impossible for him to find employment. He worried that his family, who had sacrificed so much for the Army and the nation, would be destitute.

In some cases, soldiers have been granted administrative separations from service in lieu of court-martial that allowed them to avoid sex offender registries, but Agar, the fort's staff judge advocate, said such cases were rare.

Among Jackson's character witnesses was Col. William Coultrup, a veteran of the Special Operations Command who offered a glimpse into Jackson's service with the secretive Special Mission Units, an insular group not often receptive to chaplains but who came to regard Jackson as a brother during some of the toughest fighting in Iraq and Afghanistan.

"He's been absolutely the best chaplain I've ever worked with," Coultrup said. "I would be absolutely honored to have Keith guard my back."

Col. Tom Solhjem, command chaplain of Special Operations Command, said Jackson's case was indicative of a "force fraying around the edges."

"Across the board there's been a monumental failure to understand the effects of a 10-year war," he said.

Because of the secretive nature of Special Operations Command's work and the need to maintain security clearances, Solhjem said there was "no protected place to seek help that doesn't ruin a career."

Retired Army Col. Scott McChrystal said he had known Jackson for 20 years and believed Jackson still had "enormous potential." McChrystal, who spent seven years as senior chaplain at West Point, called Jackson the "most respected chaplain in the Army."

In the end, the military judge ordered Jackson dismissed from service, the officer equivalent of a dishonorable discharge. The sentence still must be approved by the fort's commanding general, who could lessen the sentence.

Should the sentence stand, Jackson won't be able to vote or own a gun, and prosecutors estimate he'll forfeit about $1.5 million in retirement benefits. He will serve no further confinement. But he will have to register as a sex offender.