An ailing American on a solo mission to kill Usama bin Laden was going for his "last hurrah" when he flew to Pakistan to hunt the master terrorist, but he was detained by Pakistani police before he found his prey.

Gary Brooks Faulkner, a 50-year-old construction contractor from Colorado, was picked up in a remote forest near the Pakistan/Afghanistan border carrying a pistol, a 40-inch sword and night-vision equipment, according to Pakistani police.

Though he never served in the military or had combat training, Faulkner is in "great shape" and has been trained in hapkido, a Korean martial art, his brother told FoxNews.com.

But Faulkner suffers from polycystic kidney disease that has left him with only 9 percent kidney function, and he requires dialysis treatments three times a week, his family said.

"Now that he's on dialysis he realized that this is going to be his last hurrah," said Dr. Scott Faulkner, an internist in Fort Morgan, Colo. "One way or the other he knew — if his kidneys failed him, he could die on the mountain, he could take a bullet, or he could get bin Laden."

He said his brother, an avid hunter, told friends and family he was seeking much bigger game in Pakistan.

"After what Usama has done to our country and American troops and our people" — and in light of the government's failure to capture the most wanted man in the world for nearly a decade — Faulkner dedicated himself to locating and executing bin Laden and his inner circle, his brother said.

"Gary thought he's the man for the job," he said.

Faulkner was making his seventh trip to Pakistan since 2002, combing an area rumored to be among bin Laden's hiding places near the Afghan border.

He was assigned a police escort upon his arrival, but he eluded the officer and walked off on his own. He was located by Pakistani police and detained while trying to cross into Afghanistan's Nooristan region, officials said.

Faulkner's brother said he did not know how he acquired the sword and pistol Pakistani authorities said he was carrying when they detained him in a town in the Chitral Forest.

"He owns weapons in the U.S., but he did not take any of those weapons with him to Pakistan," Dr. Faulkner said. But he said his brother arms himself in preparation when he travels to Pakistan.

"He always carries swords there," Dr. Faulkner told FoxNews.com. "They're everywhere — getting a sword is easy."

Faulkner speaks only a smattering of Urdu, the main dialect of Pakistan, which he has picked up during his several trips to the region. He called his brother in Colorado after returning to the country's urban south to receive dialysis treatment.

"He contacted me about five days ago," Dr. Faulkner said. "He went down to southern Pakistan and he had to get dialysis — he was feeling pretty weak." After a round of treatment, which he normally receives every other day in the U.S., Faulkner told his brother he was feeling great again.

The Denver Post reported that Faulkner has been arrested several times in Colorado, according to Colorado Bureau of Investigation Records. He served prison sentences at least twice, in 1981 and 1986, on burglary and larceny convictions, and was sentenced to one year in jail on a domestic violence assault conviction in 1996.

More recently, Faulkner was arrested in Greeley, Colo., in 2006 on a misdemeanor "failure to appear" warrant from another jurisdiction, according to records, the Denver Post reported.

When Pakistani police picked up Faulkner on Sunday he carrying a book containing Christian verses and teachings and told them he believed God would help him find and kill bin Laden.

His brother said the book was likely the Bible. He said Faulkner does not attend church regularly and is not a religious "nut job," but he carries a Bible everywhere he goes.

"He is a deeply religious man; he believes that God's got his back, and I believe that, too," he said. Faulkner is divorced and has a son.

Dr. Faulkner said his brother is not crazy, no matter how improbable his quest may appear to those outside the family.

"I'm a physician — I would know if my brother was schizophrenic or bipolar," he said. "He's very passionate," he added, describing his brother's 8-year hunt for the terror chief as "pretty bold."

"I think more people wish they had that kind of passion in their lives."

The Associated Press contributed to this report.