(CNN) -- William Adolfo Cortez -- the man suspected in four homicides in Panama, including the death of one American -- and his wife were arrested in Nicaragua on Monday, a Costa Rican official told CNN.
The arrest was the conclusion of an international manhunt for the couple, whose nationality remained unconfirmed by authorities.
Cortez and his wife, Jane, were on the run since the body of Cher Hughes, a native of suburban St. Louis, Missouri, was found last week on his property in Panama.
The couple fled Panama to the north, traversed through Costa Rica, and were caught as they crossed the San Juan River, which acts as the boundary between Nicaragua and Costa Rica, Costa Rican Vice Minister of Public Security Jorge Chavarria said.
Cortez and his wife boarded a boat and then threw the boat's driver overboard, commandeering the vessel for themselves, Chavarria said. The Nicaraguan army stopped them as they tried to enter the country.
The couple was in Nicaraguan custody and was transported to a facility known as El Castillo, the vice minister said.
The pair face charges of stealing a boat, but an international murder warrant out for the couple is expected to result in extradition to Panama, Chavarria said.
Cortez could be American or Dutch, according to local reports, but his true nation of origin remained unconfirmed.
Hughes, who was in her early 50s, was found in a shallow grave. A second body -- which has not yet been officially identified -- was found near Hughes.
Panama police said they believed that Cortez's motive was to take his alleged victims' property.
Hughes had lived in St. Petersburg, Florida, where she owned a neon sign business, before moving to Panama.
CNN's Mariano Castillo contributed to this report.