MOUNT PLEASANT, S.C. -- A witness reported seeing the fiance of a missing woman carrying a shovel near where her burned-out SUV was found last week, police in the Charleston area say.

Dara Lee Watson, 30, was last seen Feb. 6, when she and her fiance, David Hedrick, left downtown Boone, where Watson's parents operate a store.

Police say the couple was headed back to their home in Mount Pleasant, S.C.

Watson's mother reported her missing late last Thursday. Her fiance was found dead of a gunshot wound at midday Friday. Police say the wound was self-inflicted, according to WCSC-TV in Charleston.

Harry Sewell, police chief in Mount Pleasant, where the couple lived, said Tuesday, "It is believed at this time that between Monday evening and Tuesday afternoon, Hedrick was involved in the circumstances surrounding her (Watson's) disappearance."

Sewell said the Watson and Hedrick, who began dating in 2009 and became engaged last month, were arguing about wedding plans when they left Boone.

Family members received two text messages Wednesday from Watson's phone. Otherwise, nobody heard from her after she and Hedrick left Boone. Sewell said Tuesday that police believe it was Hedrick who sent the text messages from Watson's phone.

Watson's burned-out SUV was found Wednesday in Francis Marion National Forest, northwest of Charleston. Police told WCSC on Tuesday that a witness saw Hedrick near North Creek Drive in the national forest, not far from where Watson's vehicle was discovered. The witness said Hedrick was carrying a shovel.

Sewell said investigators believe Hedrick then hitched a ride back to the couple's residence.

Police searched in the Francis Marion National Forest on Sunday and returned to the area Tuesday, concentrating their efforts around Iron Swamp and Clayfield roads. There was no report on whether they found anything related to the search.

After receiving the missing person report late Thursday, police called Hedrick at his home Friday.

A few hours later, according to WCSC, two of Hedrick's friends went to his home to speak with them. They told WCSC they heard a gunshot as they were climbing the steps at the three-story house. Hedrick's body was discovered in the bedroom, with a handgun nearby.

Watson works with a medical consulting company. Hedrick was CEO of a bond surety corporation.