(Wednesday) CARTHAGE, Mo. -- Matthew Laurin, 19, of Springfield and Darren Winans, 21, of Jasper are arrested and charged for the murders of Robert and Ellen Sheldon in their home. Investigators said at a news conference on Wednesday that they believe Laurin and Winans stabbed the couple to death on Oct. 11, 2008, to cover up a burglary at the couple's gun and archery shop next door to their home just outside Carthage.

Laurin and Winans are each charged with two counts of first-degree murder, two counts of armed criminal action and one count of burglary. A judge ordered that they be held without bond.

Winans was arrested on July 1 on a charge of stealing a gun by shoplifting from the Sheldons’ Old Cabin Shop last Sept. 23. He's been in the Jasper County jail since then. Another man was arrested last year for stealing the gun. Officers arrested Laurin on Tuesday at his home in Springfield at 2738 S. Stewart Ave.

“They may have considered the Sheldons an easy target, maybe, since they walked in there and walked out with a gun,” said Jasper County Sheriff Archie Dunn. “They may have thought, ‘This is easy. We can do it again.’”

According to the probable cause statement used as the basis for the charges, investigators said Laurin admitted in an interview that he and Winans stabbed the couple "multiple times with a knife." The news conference is the first time that Dunn or others revealed publicly how the Sheldons were killed. Investigators are still looking at what may have been taken in the burglary.

“They may have felt like they had to leave the scene before they were finished,” said Dunn.

Deputies seized Laurin’s car from his home in Springfield. They believe it was the car seen at the Sheldons’ home on the Saturday night of the murders. Officers also executed a search warrant at Laurin’s home on Wednesday.

It was two anonymous tips on the Jasper County Sheriff’s Department tips line that helped lead to the suspects. Dunn wouldn't say much about the tips but he said the first one arrived in December. Investigators couldn't do much with it when a suspect refused to talk to detectives and asked for a lawyer. The second tip arrived in May.

The Sheldons' family offered a $40,000 reward for information that leads to arrests and convictions of the murderers. For the relatives, the arrests bring relief.

“It was absolutely a feeling of elation like I don’t think I’ve ever had before. These nine months, looking over your shoulder, not knowing what happened, who did it, basically a .45 has been my best friend ever since that happened. I’ve just carried something with me constantly just in case, because we don’t know who, why, how, anything about it,” said Bob Sheldon Jr., a son of the murder victims.

Investigators also are glad to finally have a break in the case.

"I’d kick myself in the butt every day when we didn’t get this solved, because that’s what I’m elected to do. We all felt the same way. We all took this home with us," said Dunn.

The sheriff says this investigation is nowhere near over. Investigators have a lot more to do, and say there may be a possibility of additional suspects.