Mark Koster

Mark Koster (courtesy Iowa Dept. of Public Safety)

Mark Edgar Koster

Homicide — ARREST MADE, TRIAL PENDING

Mark Edgar Koster
58 YOA
Weight: 140 lbs.
Height: 5’10”
Hair: Grey
Eyes: Blue
610 N. 5th St.
Sac City, Iowa
Sac County
Went Missing: July 4, 2009
Declared Legally Dead: October 10, 2011
Remains Found: November 5, 2012

 

 

UPDATE

New trial date set for man accused of killing friend, hiding body in basement

Wednesday, Dec. 10, 2014, from the Omaha World-Herald

A new trial date has been set in the case of John David Green, accused of killing longtime friend Mark Koster and leaving the body in a basement where it wasn’t found for three years.

The new trial is set to begin March 30, 2015. Green is charged with first-degree murder in the 2009 death of Koster of Sac City, Iowa. The new trial date was scheduled after District Court Judge Gary McMinimee declared a mistrial Tuesday, Dec. 9, when a defense attorney objected to a statement made by Sac City Police Chief John Thomsen.

The prosecution and defense made their opening arguments in the first trial Tuesday morning at the Webster County Courthouse in Fort Dodge, and Thomsen was the second — and the last — to testify, the World-Herald reported in a separate Dec. 10 story.

When Sac County Attorney Ben Smith asked Thomsen about themes investigators used while questioning Green, Thomsen used the words “bad people” and the defense argued the comment was in reference to Green. The prosecution contended it was a general statement, but the judge declared a mistrial.


PREVIOUS UPDATES

Arrest Made in 2009 Sac City Homicide

On March 26, 2014, the Sac City Police Department and agents with the Iowa Division of Criminal Investigation announced in a press release that they had interviewed and arrested John David Green, 54, in Orange Park, Florida, for the June 2009 murder of Sac City resident Mark Koster.

john-david-greenCourtesy Sioux City Journal / Clay County (Fla.) Sheriff’s Office
John David Green

Green had lived with Koster for a short time in 2009.

Koster’s family believed he’d left the Sac City area for a period of time during the summer of 2009. They became concerned when they didn’t hear from him for several months, and filed a missing persons report with the Sac City Police Department.

Koster, who was 58 at the time he went missing, was declared dead in 2011, and in May 2012 his family sold the 610 N. 5th St. home.

While remodeling the basement in November 2012, the new homeowner discovered Koster’s skeletal remains concealed in a basement wall.

In a press conference held Tuesday, April 1, 2014, Sac County Attorney Ben Smith said it was several months before they identified Koster’s former roommate, John Green, as a suspect in the case, and began collecting evidence.

After locating Green at a Florida casino, officials asked him to come in and answer a few questions. Green then admitted to choking Koster to death with a baseball bat after a fight. He told investigators he hid Koster’s body in the basement, cleaned the crime scene, and had then skipped town a few days later.

Green has been charged with one count of first-degree murder and was extradited from the Clay County jail in Florida to Sac County’s jail on Friday, March 28, 2014. He had his initial appearance before a judge Saturday morning, March 29, and on Thursday, April 17, entered a written “not guilty” plea.

Information and questions should be directed to Iowa DCI SAC Mitch Mortvedt at (402) 650-7458.

Read the Arrest Report


Case Summary compiled by Jody Ewing

Mark Koster disappeared from Sac City, Iowa, sometime during the summer of 2009, and was listed on the Iowa Dept. of Public Safety’s Missing Person Information Clearinghouse as having been reported missing to the Sac City Police Department on July 4, 2009. The MPIC also stated that “Mark Koster smokes a pipe,” and was “last seen with a friend from Florida.”

Koster resided at 610 N. 5th Street in Sac City, and the friend — identified only as “Tom” in other published reports — allegedly was from either Florida or Texas but had been living with Koster in the three months prior to Koster’s disappearance.

“Tom” was never seen again after Koster went missing.

Daniel Koster, the victim’s brother, discovered his brother was missing when the Sac City utility department contacted him about his brother’s unpaid utility bills.

A search warrant served on Koster’s home following his disappearance showed no signs of foul play but revealed all of Koster’s clothes still present in the home, along with all his personal possessions, including a pipe and tobacco. Koster’s vehicle was found in the garage at the victim’s residence.


Sac County in Iowa

Sac City in Sac County

Neither Koster’s bank account nor his debit card showed any activity after he went missing.

Despite extensive efforts to locate Koster — including searches and investigations by the Sac County Sheriff’s Office, the Sac City Police Department and the Iowa Division of Criminal Investigation (DCI) — no evidence developed to indicate Koster was still alive.

Koster Declared Dead

In 2011, Daniel Koster petitioned the Iowa District Court for Sac County to have his brother declared dead from accidental or other violent means.

The Court summoned and empaneled a jury of six qualified persons to inquire into the facts surrounding Koster’s disappearance to see if reasonable grounds existed to have him legally declared dead.

The jury found clear and convincing evidence that Mark Edgar Koster suffered death by accidental or other violent means, and Koster was declared dead as of October 10, 2011.

Remains Found

On Monday, November 5, 2012, a new homeowner renovating Koster’s former Sac City home discovered human skeletal remains concealed in the home’s basement. He immediately contacted Sac City Police.

Lesly Gehlsen of Carroll, Iowa, had purchased the residence in May 2012.

In a November 6 press release, Sac City Chief of Police John Thomsen said the items were being sent to the Iowa State Medical Examiner’s Office for identification.

On Thursday, November 8, the Sac City Police Department announced the remains had positively been identified as those of Koster. The remains were identified using dental records, and were to remain in the custody of the Iowa State Medical Examiner’s Office in Ames.

The Sac City Police Department called the circumstances and location of Koster’s remains “suspicious,” and said the case is currently under investigation.

“(His death) is going to be investigated no matter what because of the suspicious nature from where the body was recovered,” Thomsen said in a Sioux City Journal article dated November 8, 2012. “The main thing will be to find the friend, who was reported living with him. His name’s Tom, and he’s either from Florida or Texas.”

Police said attempts to locate the man for questioning never turned up any solid leads.

A 2010 full search of the home by DCI officials had failed to turn up any DNA. No one had lived in the home since Koster’s disappearance.

Due to the condition of the remains, officials said autopsy results could take up to two months to become available.

The Journal located one of Koster’s sisters, who said the family was saddened but relieved to have some closure in the case.

“We hope he is resting in peace,” Jane Koster, of Des Moines, told the Journal.

Officials Make Arrest, Trial Scheduled

On March 25th, 2014, officers with the Sac City Police Department and Iowa DCI agents interviewed and arrested John David Green, age 54, of Orange Park, Florida, in connection with Koster’s June 2009 death.

In a press conference held Tuesday, April 1, 2014, Sac County Attorney Ben Smith said it was several months before they identified Koster’s former roommate, John Green, as a suspect in the case, and began collecting evidence.

“The Sac City Police Department and the Division of Criminal Investigation worked it diligently, collecting DNA evidence, executing a search warrant,” Smith said. “In the end, it was good. It was good evidence to have.”

After interviews with family and friends, Sac City authorities and the Iowa DCI began tracking Green, using the assistance of law enforcement agencies in four states across the country.

“Finding John Green wasn’t as important as collecting all the evidence and making sure all the ‘i’s were dotted, ‘t’s were crossed before law enforcement went down and confronted him with what they had,” Smith said.

Authorities located Green at a casino in Orange Park, Florida, and asked him to come in and answer a few questions.

Green then admitted to choking Koster to death with a baseball bat after a fight. He told officials he hid Koster’s body in the basement, cleaned the crime scene, and then skipped town a few days later.

“Along with current technology, it was good old fashioned police work by the Sac City Police Department, and the DCI, and our division of intelligence as well,” Mitch Mortvedt, Iowa DCI, said during the April 1 press conference.

Smith said that while their work can never undo what happened in the Sac City home years ago, at least at the end of it all, there was closure waiting for Mark Koster’s family.

“What I can tell you is that law enforcement never gave up, and probably the most important thing is that the family now has closure,” he said.

The investigation was a cooperative effort between the Sac City Police Department, the Iowa Division of Criminal Investigation, the Iowa Division of Intelligence, the Florida Department of Law Enforcement, the Georgia Bureau of Investigation, the North Carolina State Bureau of Investigation, the Clay County (Florida) Sheriff’s Office, the Sac County Attorney’s Office and the Iowa Attorney General’s Office.

Courts Proceedings/Trial Timeline

On March 25th, 2014, officers with the Sac City Police Department and Iowa DCI agents arrested 54-year-old John David Green of Orange Park, Florida, in connection with Koster’s June 2009 death. He was charged with one count of first-degree murder.

On Friday, March 28, 2014, Green was extradited from the Clay County jail in Florida to Sac County’s jail. He had his initial appearance before a judge Saturday morning, March 29, 2014.

On Thursday, April 17, 2014, Green pleaded not guilty via a written plea in Sac County District Court.

The June 25, 2014 first-degree murder trial was rescheduled and set to begin in Sac City, Iowa, on December 8, 2014.

On Friday, October 31, 2014, District Judge Gary McMinimee granted public defender Charles Kenville’s request for a change in venue. Kenville said it would be hard for his client to receive a fair trial in Sac County due to extensive media coverage of the case.

Prosecutors did not resist the request, and McMinimee moved the murder trial from Sac City to Fort Dodge in Webster County.

Jury selection for Green’s trial began Monday, Dec. 8, 2014.

Opening arguments in the case began Tuesday morning, Dec. 9, 2014, and by early afternoon, Judge McMinimee declared a mistrial based on testimony from Sac City Police Chief John Thomsen.

In describing an investigative technique, Thomsen referred to “bad people,” and the defense argued the comment was in reference to Green.

On Wednesday, Dec. 10, 2014, the World-Herald reported the new trial is set to begin March 30, 2015.

Green continues to be held without bond in the Sac County Jail.

About Mark Koster

Mark Edgar Koster was born in Lake City, Iowa, May 9, 1951, the son of Edgar and Delores (Bachman) Koster. He was one of 11 children.

In 1957, the family moved to Stacyville, Iowa, where Mark attended Visitation Grade School and Marian High School.

Mark graduated from St. Ansgar High School in 1969 and Mason City Junior College in 1972. He served two years in the U.S. Marine Corps and was honorably discharged in 1974.

He enjoyed fishing and playing cards.

Mark lived in Texas and Florida before settling in Sac City, where he resided until his death.

Mark is survived by his father, Edgar Koster, Des Moines; sisters Karen Cain, Janesville, Wis., Jane Koster, Des Moines, Nancy (Mike) Teasdale, Edina Minn., Kristy Koster, Ames, and Mary (Efren) Vintimilla, Asheville, N.C.; and brothers Daniel Koster, Wall Lake, Dale (Jennifer) Koster, Chandler, Ariz., Paul (Carole) Koster, Bloomington, Minn. and Craig (Naoise) Koster, Eden Prairie, Minn.; five nephews; 12 nieces; two great-nephews; and many aunts, uncles and cousins.

Mark was preceded in death by his mother, Delores Koster, in 2000; brother, Pat Koster, in 1988; and brother-in-law, Larry Cain in 2009.

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Add a Comment

6 Responses to Mark Koster

  1. Someone says:

    Some search, if he was in the house all along. How sad.

    • Hello, I am a new member if Iowa Cold Cases. When it is determined who the victim is in the home we will provide that information. Please feel free to email our website with any information. Thank you so much.

  2. Sylvia Allen says:

    Between Pipl and Peoplefinders, it shows that Mark lived in SacCity, IA: Ocoee, FL; Dallas, TX and Lewisville, TX (just outside of Dallas). One site also showed a possible name of “Mark C Oster” which could have simply been a typo or misprint, or may have nothing to do with him at all.

  3. A says:

    Do you know if Mark ever resided in Sioux City, Iowa? He looks very familiar.

    • Jody Ewing says:

      In response to “A’s” question, I’m not sure if Mark Koster ever resided in Sioux City, but he may look familiar due to the Sioux City Journal’s coverage on his case.

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