ADAMS RUN — A mother of three who worked in a family convenience store in rural Charleston County was killed in a robbery Thursday, and investigators have released photos of the man they believe killed her.

Crystal Johnson, 37, of the Adams Run community, was a part-time clerk at D&V Convenience Store at 8008 Savannah Highway. It’s a cinder-block building several miles south of Ravenel.

A customer walked into the store and found her body in the bathroom sometime before 4 p.m. Thursday, Sheriff Al Cannon said at the scene. A 911 operator got a call that a woman had been killed in the store about 3:50 p.m., he said.

Investigators believe the clerk was killed about 1:45 p.m., sheriff’s Maj. Jim Brady said. A man walked in and shot her, then robbed the store, he said.

Dozens of neighbors and family members stood along the highway across from the store for several hours after the crime while investigators processed the scene before removing the body around sunset.

Johnson’s sister, Christie Moultrie, 38, had been called to the store earlier to identify the body. She said the cash drawer was sitting on the counter and her sister was lying on the bathroom floor with a big gash in her head.

“I knew she was gone when I saw all that blood,” she said.

Cannon confirmed that the clerk was wounded in the head. An autopsy will be conducted today to determine her cause of death, Charleston County Coroner Rae Wooten said.

Johnson was married with three children, ages 15, 12 and 9, her sister said. Their aunt owns the store and Johnson worked there part time.

“Whoever did this, I hope they suffer the maximum penalty,” Moultrie said. “We did everything together.”

The suspect and his car were captured on the store’s video camera, and the sheriff’s office released photos Thursday night. The suspect was believed to be driving a blue four-door sedan, possibly a Ford, Brady said.

Anyone with information is asked to call Detective Charles Lawrence at 743-7200 or leave an anonymous tip at Crime Stoppers at 843-554-1111.