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Fla. man arrested in Sac City murder case

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SAC CITY, Iowa | Family members of a Sac City, Iowa, man killed in 2009 are thankful a man suspected in his death has been arrested.

Mark Koster, 58, was found dead in his basement in November 2012. Authorities said Wednesday they believe his friend, John David Green, 54, killed him in 2009 and hid his body in the house.

Green was arrested Tuesday at a dog racetrack in Orange Park, Fla., on a felony charge of first-degree murder.

“We’re grateful,” said Koster’s sister Nancy Teasdale, of Edina, Minn., when contacted by the Journal.

State and local police began searching for Green after Koster’s body was found hidden in the basement of his home in 2012.

Koster's family reported him missing from Sac City in 2010. He was believed to have left the Sac City area in 2009, and his family was concerned because they hadn't heard from him for several months.

He was declared legally dead in 2011. His house on North Fifth Street was sold in May 2012.

The new homeowner found Koster's remains while remodeling the basement in November 2012.

At the time of the discovery, officials believed they were looking for a friend of Koster's named Tom. Investigators later learned Tom was an alias Green used, said Mitch Mortvedt, resident agent-in-charge for the Iowa Division of Criminal Investigation.

The search for Green led investigators to Kansas City and, eventually, to the city of Orange Park, just south of Jacksonville, Fla. Police agencies in North Carolina, Georgia and Florida also assisted with the search.

Florida investigators believe Green had been living in a camper at the Orange Park Kennel Club, a greyhound racetrack, for two days, possibly arriving from the Orlando, Fla., area, said Clay County (Fla.) sheriff’s spokeswoman Mary Justino.

Green's address is listed in arrest records as Blairsville, Ga. The city is just south of the Georgia-North Carolina line.

Officials won’t say what reason Green had for allegedly killing Koster. They also haven’t said how Koster died.

Green was being held Wednesday without bail. Extradition proceedings to return him to Iowa are pending.


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