“I mean it’s sad, you know we’re a couple days before the Thanksgiving holiday,” Mr. Kosinski said.
In a shooting over the weekend, five people were killed at an L.G.B.T.Q. club in Colorado Springs, Colo.
Earlier this month in Charlottesville, Va., three members of the University of Virginia football team were killed by a former football player, who opened fire in a garage, the authorities said.
Photos and videos from the scene of the Walmart shooting showed officers huddling around the entrance of the building on Sam’s Circle, with numerous police vehicles parked in the large lot of the store, which is off Battlefield Boulevard. A large inflatable Santa Claus stood outside the store.
Mr. Kosinski said that officers were searching for more victims inside the Walmart shortly after midnight on Wednesday.
He noted that the large store “had a lot of hiding spots” for shoppers who had possibly sought cover during the shooting.
“People could get scared, they could be hiding,” Mr. Kosinski said. “We want to make sure that everyone is accounted for.”
The authorities directed relatives of people affected by the shooting to the Chesapeake Conference Center. Local TV stations reported that a chaplain would be there.
The Walmart supercenter where the shooting occurred is one of several in southeastern Virginia. It includes a grocery store, a pharmacy, a bank, a bakery and a deli, among other businesses. Mr. Kosinski told reporters that the Walmart was “very, very large,” although he did not know the square footage.
Chesapeake, a few miles south of Norfolk, had a population of about a quarter of a million people last year, according to the United States Census Bureau. It is near Virginia’s Atlantic coast and the border with North Carolina.
Sen. Mark Warner of Virginia, a Democrat, said in a statement that he was “sickened by reports of yet another mass shooting.”
L. Louise Lucas, a Virginia state senator, said on Twitter that she was “absolutely heartbroken that America’s latest mass shooting took place in a Walmart in my district in Chesapeake.”
“I will not rest,” she said, “until we find the solutions to end this gun violence epidemic in our country that has taken so many lives.”
This is a developing story. It will be updated.