The victim, identified as David Long, 40, of Wauna died Saturday at Tacoma General Hospital, where he has been ever since the shooting.
The accused shooter, Laura K. Sorenson, 20, walked into the Peninsula Market at Lake Kathryn Village just before 1 p.m. on Aug. 11 and started firing at customers before being tackled to the ground, according to prosecutors.
Long was the most seriously injured of the three victims. He was hit in the torso by a bullet that went through his body and out his back.
One other man was hit in the leg by gunfire. A third man, a store cashier, was wounded from a ricochet.
Sorenson currently is facing two attempted murder charges and an assault charge in the shooting. Prosecutors weren't available Saturday to comment on the possibility of charges being increased now that one victim has died.
According to court documents, witnesses told police that Sorenson said something about "killing" people prior to pulling out a revolver from her purse and firing four to five shots.
A woman who came into the store was able to hold Sorenson down until police arrived, documents said. Investigators said Sorenson had already run out of bullets and put down the gun.
After the shooting, Sorenson revealed to detectives she has a mental condition and is on medication, documents said, adding she wanted to kill herself and wanted to know what it felt like to kill someone else first.
She told detectives she went to her grandmother's home, grabbed a revolver, then went to the market, according to court documents.
Sorensen also told detectives she had been molested as a young child and hated men, prosecutors said.