The manhunt for Joseph C. Palczynski, suspected in the shooting deaths of four people last week, intensified last night as police combed the woods and marshland of eastern Baltimore County using helicopters, police dogs and scores of officers patrolling area roads.

Police said they believe Palczynski, an avid outdoorsman, may be camping near Bowleys Quarters in hundreds of acres that include Gunpowder State Park.

Police set up an automated dialing system yesterday to 1,700 homes in the area to alert residents to the manhunt and provide them with Palczynski's description, said Baltimore County police spokesman Bill Toohey.

"Please lock your doors. Keep a lookout for a suspect matching the description. This suspect is armed," said the automated message, read by Philip R. Canter, chief of the department's crime analysis unit.

County police have received almost 500 calls to a hot line set up four days ago to help with the manhunt -- 410-887-5903 -- and hundreds of other calls to 911, Toohey said.

About 100 law enforcement officers searched yesterday for the fugitive. County police officers were assisted by FBI agents, Maryland State Police, Maryland Natural Resources Police, and Harford County sheriff's deputies, Toohey said.

Palczynski, 31, a convicted felon with a history of mental illness and domestic violence, is wanted in a rampage that began Tuesday night with the shooting deaths of George Shenk, 49, and Gloria Jean Shenk, 50, a Bowleys Quarters couple who had taken in Palczynski's former girlfriend, Tracy Whitehead.

Palczynski is accused of kidnapping Whitehead, 22, from the Shenks' home and killing a neighbor, David Meyers, 42, who came to her aid.

Palczynski is also a suspect in the shooting death of Jennifer L. McDonel, 37, in an attempted carjacking Wednesday night in Chase. A 2-year-old riding in a passing car was also wounded.

Yesterday, police were highly visible in Chase, where Palczynski's mother lives. Wanted posters were tacked up at dozens of businesses and officers were working out of a command center set up at the Middle River Volunteer Fire Station on Leland Avenue. Several officers with police dogs were on patrol last evening.

Unfamiliar faces were scrutinized. When a reporter drove into the neighborhood of bungalows and Cape Cods that includes the home of Patricia Long, Palczynski's mother, he was stopped by a county officer. Three officers in marked police cars quickly arrived as backup.

Toohey said that high winds prevented the use of a county police helicopter much of yesterday. A heavier state police helicopter was able to assist, but to no avail.

The search for Palczynski is difficult for two reasons, police said: the miles of thickly wooded terrain and the suspect's familiarity with it.

"He's a skilled and resourceful man. He's an experienced outdoorsman. He's physically fit and seems to be comfortable out there," Toohey said. "It's going to take awhile, but we know we'll find him."

Police said they believe that Palczynski rode a freight train early Friday to north of Richmond, Va.

He is thought to have broken into an unoccupied home in southwestern Caroline County, Va., stealing a handgun, shotgun, food and a pickup truck. When the truck ran out of gas near Wolford, Va., he walked to a house and forced a man at gunpoint to drive him back to Middle River, police said.

The man, William L. Terrell, told the authorities that they stopped on the way for him to buy food and supplies for Palczynski, police said.

Toohey would not discuss whether Terrell might face charges for helping Palczynski by purchasing supplies for him.

Toohey said Palczynski apparently has enough food and camping supplies, including a sleeping bag, to survive in the woods for at least several days. He is believed to have a battery-operated color television set and a .22-caliber handgun, police said.

Toohey declined to say why Palczynski might have returned to the area after fleeing to Virginia but suggested that the suspect's familiarity with this area might be a factor: "He seems to want to be close to those places he knows."