SAC CITY - The return of a Georgia man suspected in a 2009 murder means closure for the family of victim Mark Koster, Sac County Attorney Ben Smith said Tuesday.
John D. Green, 54, of Blairsburg, Ga., was extradited back to Iowa late Friday night after his arrest in Orange Park, Fla., on March 24.
Green is facing one count of first-degree murder in connection with the 2009 death of Koster, 58.
Smith made his comments at a Tuesday morning press conference at the Sac County Law Enforcement Center.
He said Green admitted to law enforcement that he killed Koster.
"There's not a lot we can tell you above and beyond that or what's already in the complaint," Smith said. "But I can tell you that law enforcement never gave up and probably the most important thing is the family now has closure."
Koster was initially reported as a missing person in 2010 after his family hadn't heard from him in several months. According to Smith, Koster "had a propensity to just pick up and leave."
Koster's badly decomposed remains were found buried in his basement in November 2012 after his house was sold, and the new owners were cleaning up.
Sac City Police Chief John Thomsen said interviews with friends and family led to Green, who had worked at a convenience store with Koster back in the 1980s, being identified as a suspect.
"It took us a couple of months to identify him as our lead suspect," Thomsen said.
While Smith declined to discuss specifics about what led authorities to suspect Green, he did say investigators were helped by a number of factors.
"We used the best modern technology available to us," he said. "This isn't something that was accomplished just by the people sitting here at this table."
It was also "good, old-fashioned police work" that led to Green being located, according to Special Agent in Charge Mitch Mortvedt, of the Iowa Division of Criminal Investigation.
"As you interview people, you get more information, and it builds on that," Mortvedt said. "Multiple officers were traveling and making arrangements, and it took quite a bit of coordination. There was a lot of cooperation that the Sac City Police Department and DCI received from out-of-state agencies with a crime that didn't happen in their jurisdictions."
Though Green's arrest happened more than a year after Koster's remains were found, Smith said it was important to not rush the case.
"Finding John Green was not as important as finding all the evidence and making sure all the T's were crossed and I's were dotted," he said. "Investigators were able to confront him with what they had."
He declined to say whether or not Green claimed to have killed Koster in self-defense.
The trial information in Green's case is expected to be filed later this week, according to Smith. In addition to the murder charge, Smith said Green could also be charged with obstruction of justice.
"That would be for towards the very end, making it look as if Mark Koster had left," Smith said. "We can't get any more details as to that, but I do anticipate filing that charge."
He added that assistant Iowa attorney general Doug Hammerand will be assisting in Green's prosecution.
Hammerand also helped prosecute the 2011 murder trial of Tracey Richter, and the 2013 murder trial of Kirk Levin. Both Richter and Levin are now serving life in prison after being convicted of first-degree murder.
Even though this is the third murder case to be prosecuted in Sac County since 2011, Smith said that shouldn't be a reflection of the county's image.
"If you look at the things that have happened in the last three to four years here, they're not people that lived here," Smith said. "Kirk Levin wasn't from here. John David Green is not from here. Tracey Richter wasn't from here."
He believes those cases prove how determined investigators are to solve crimes in the county.
"I think the law enforcement here is more aggressive which necessarily puts these sorts of things in the limelight," he said.
In addition to local agencies, Smith said the North Carolina Bureau of Investigation, Kansas City Metropolitan Police Department, Georgia Bureau of Investigation, Florida Department of Law Enforcement and the Orange Park Sheriff's Department also assisted in the investigation.