A former Wright City R-II superintendent is accused of murdering a couple in Springfield, according to authorities.

Mark Porter, 53, of Ozark, was arrested and charged Friday with two counts of first-degree murder in the May 1 deaths of Gary Tyrrell, 60 and his wife, Jan, 61. He is being held without bond in the Greene County Jail.

Gary Tyrrell was shot to death and his wife died of apparent blunt force trauma to the head, Greene County Prosecutor Dan Patterson said in a news release.

Porter was superintendent in the Wright City R-II School District from 2005 to 2008 until retiring to enter into the private sector. Following his retirement, he has worked for the IBM Corporation and RSP Associates, as well as an adjunct instructor at William Woods University where he taught secondary administration courses, according to his LinkedIn site.

Prior to working in Wright City, he spent two years as superintendent in Mountain Grove, located about an hour east of Springfield. During that stint, Gary Tyrrell was assistant superintendent.

The news of Porter’s alleged involvement stunned many in the area.

“From most of folks here, folks that knew him fairly well, are shocked,” said current R-II Superintendent Dr. Chris Gaines, who replaced Porter. “It really surprised them.”

Gary Tyrrell dealt in precious metals and gemstones and the couple’s home was filled with high-end items, police said. The couple and Porter were longtime friends and Porter was one of the few people allowed into their home. However, Gary Tyrrell had recently declined to loan Porter $250,000, according to charging documents.

Officers discovered the couple’s bodies after their daughter reported she had been unable to contact them. Police said they found no signs of forced entry at the home. It appeared that someone had tried to break into a safe in the couple’s basement but other expensive items in the house were not touched, according to the probable cause statement.

Investigators also discovered Porter had sold $18,531 in silver coins the day after the couple’s bodies were found, and documents in the Tyrrell’s home showed they had silver coins valued at $22,000.

Investigators linked Porter to the crime when DNA found on a latex glove found near Jan Tyrrell’s body matched DNA on a coffee cup that had been discarded by Porter and retrieved by an undercover officer, according to the court documents filed by prosecutors.

Porter told police before his arrest that he had planned to meet Gary Tyrrell at a McDonald’s on April 30 and when Tyrrell did not show up, he went to the couple’s home but was unable to contact them.

The Associated Press contributed to this story.