Robert Joseph Legendre, 27, was captured in Caruthersville, Mo., said Fred Scaletta, an Iowa prisons spokesman. On Thursday,near Chester, Ill.
Authorities said they used a homemade grappling hook to scale an unguarded section of the prison's limestone walls and somehow got around a wire that is supposed to activate an alarm when touched.
Few details of Legendre's capture were immediately available.
"He is in custody with officials in southern Missouri, that's all we know right now," said Jim Saunders, spokesman for the Iowa Department of Public Safety.
Police in Randolph County, Ill., said the convict captured earlier, Moon, was found sleeping in a car near Chester, about 50 miles southeast of St. Louis. When an officer stopped to run on a check on the car's license plates, Moon drove off. After a short chase, Moon jumped out of the car and ran into the woods, where he was caught, police said.
Moon crashed the car into a tree, Vilsack said.
Moon was convicted of first-degree murder in 2000 for shooting his roommate, Kevin Dickson, during a drug deal in 1999. Legendre was convicted of attempted murder in the beating of a cabbie, as well as first-degree kidnapping and a charge called use of deadly weapons enhanced.
Moon was returned to Iowa later Thursday and is back at the prison, Scaletta said.
Legendre was convicted in Nevada in the kidnapping and attempted murder of a Las Vegas cabbie and was transferred to Iowa last year. Moon was convicted of murder in 2000 for shooting his roommate during a drug deal in 1990 and was serving a life sentence.
Fred Scaletta, a corrections department spokesman, said the inmates used upholstery webbing, a material used in the furniture production at a Prison Industries facility inside the prison, to scale the wall.
The guard tower in that section had been unmanned since 3 p.m. — a policy that Fraise said was implemented due to state budget cuts.
"I don't want to say I told you so, but those towers were put there for security, and when you don't man those towers, that puts a hole in your security," Fraise
Based on Moon's account, police had said they believed the pair immediately split. The towns where the two men were caught are about 120 miles apart.
An investigation of the escape was under way, Gov. Tom Vilsack said. "There were a series of mistakes that were made," he said.
A corrections official has said the guard tower near the spot where the inmates went over the wall was unmanned at the time because of budget cuts.
The Iowa State Penitentiary, just a block from U.S. Highway 61 and close to a bridge that crosses the Mississippi River to Illinois, opened in 1839 and is the oldest prison in the United States west of the Mississippi River. Its maximum security section has a capacity of 550 inmates, and including minimum security and other sections the prison has an overall capacity of 1,166, Welder said.