“The uterus is missing.” Moore looked at Tierney.

The M.E. nodded. “It’s been removed.”

Moore withdrew his hand from the body and stared down at the wound, gaping like an open mouth. Now Rizzoli thrust her gloved hand in, her short fingers straining to explore the cavity.

“Nothing else was removed?” she asked.

“Just the uterus,” said Tierney. “He left the bladder and bowel intact.”

“What’s this thing I’m feeling here? This hard little knot, on the left side,” she said.

“It’s suture. He used it to tie off blood vessels.”

Rizzoli looked up, startled. “This is a surgical knot?”

“Two-oh plain catgut,” ventured Moore, looking at Tierney for confirmation.

Tierney nodded. “The same suture we found in Diana Sterling.”

“Two-oh catgut?” asked Frost in a weak voice. He had retreated from the table and now stood in a corner of the room, ready to bolt for the sink. “Is that like a — a brand name or something?”

“Not a brand name,” said Tierney. “Catgut is a type of surgical thread made from the intestines of cows or sheep.”

“So why do they call it catgut?” asked Rizzoli.

“It goes back to the Middle Ages, when gut strings were used on musical instruments. The musicians referred to their instruments as their kit, and the strings were called kitgut. The word eventually became catgut. In surgery, this sort of suture is used to sew together deep layers of connective tissue. The body eventually breaks down the suture material and absorbs it.”

“And where would he get this catgut suture?” Rizzoli looked at Moore. “Did you trace a source for it on Sterling?”