The man who killed himself after being questioned in the disappearance of a Hilton Head couple scratched a suicide note on a bedsheet and lined the bathtub where he was found with a comforter and pillow before stabbing and cutting himself several times.

Police released the new details on Wednesday, but still didn't reveal the contents of either of the two notes discovered near the body of Dennis Ray Gerwing — a business associate of John and Elizabeth Calvert.

Authorities believe Gerwing may have been the last one to see the couple before they vanished March 3. He committed suicide shortly after he was named a person of interest in the case and interviewed by police.

Gerwing wrote two notes, including the one scrawled on a bedsheet. The steak knife he apparently fatally stabbed himself with was found near the tub.

Pathologists classified it as a "motivated suicide," Beaufort County Sheriff P.J. Tanner told reporters at a press conference Wednesday. He declined to define the term.

The fresh details in the case came out of police reports made public Wednesday morning and the news conference.

In spite of recent media stories speculating that Gerwing may have been killed by someone else, there is no question that he took his own life, according to Tanner.

"No one else is involved," he said. "Let’s stick to the facts. The Nancy Drew murder mystery stuff that’s been going on for the past few weeks is not helping us. It’s creating some challenges for us that we do not need."

The Calverts live part time on a yacht at the Harbour Town marina in Hilton Head they lease and manage.

Tanner said the likelihood of finding the couple alive was decreasing.

"The first 24 to 48 hours is extremely important to every investigation," he said. "With every day that we move forward, it diminishes the possibility of finding them alive."

FOX News' Catherine Donaldson-Evans and The Associated Press contributed to this report.