Residents Are Warned to Expect a Long Search for the Maine Shooting Suspect

Law enforcement officers rushed from place to place across southern Maine on Friday, their patrol cars and helicopters swarming on any reports that might indicate the presence of Robert R. Card Jr., the suspect in the mass shooting that killed 18 people in Lewiston.

The authorities asked residents for patience during the extended lockdowns in the city and nearby communities, but people continued to feel jumpy and uncertain. Gaggles of news reporters followed officers in camouflage or tactical gear as they investigated each new lead.

Officers drew considerable attention on Thursday when they executed search warrants at a farm owned by some of Mr. Card’s relatives, prompting officials to say at a news conference on Friday that such tactics were typical, and would probably be repeated at other locations.

“We know that this is difficult for everybody,” said Michael Sauschuck, the state’s public safety commissioner. His office would schedule daily briefings on search operations, he announced, suggesting that the manhunt could extend for some time.

Mr. Sauschuck showed reporters enlarged aerial images of several locations and said that local, state and federal law enforcement officers planned to search those spots on Friday. They included the two shooting scenes and a stretch of the Androscoggin River near a boat launching ramp in Lisbon where police found a vehicle linked to Mr. Card that they sought in the first few hours after the shootings.

Divers would be searching underwater, and a power utility that operates dams along the river would lower water levels to make the search easier, Mr. Sauschuck said.

In addition to standard grid searches, in which groups of officers section off areas of land to check systematically, teams would also be conducting tactical searches that in some cases could involve armored vehicles, Mr. Sauschuck said, warning residents not to be unduly alarmed.