BOWIE, Md. -- Playgrounds and parks were empty, shoppers darted warily across parking lots and shaken parents escorted children to and from school Tuesday, a day after a youngster was wounded by the sniper roaming suburban Washington.

Security firms across the region reported a surge in interest. About 50 Starbucks stores removed their outside seats. And mental health counselors scrambled to set up crisis hotlines for people upset by the string of shootings that have left six people dead and two wounded since last week.

"This is a person who is shooting elderly men, shooting women and now shooting little children," Gov. Parris Glendening said. "This is the act of an absolute coward."

The latest victim, a 13-year-old boy, remained in critical but stable condition Tuesday with a wound to the chest. He was shot early Monday after he was dropped off at school.

Few solid clues

With few solid clues or witness accounts, federal, state and local investigators are sifting through more than 7,500 phoned-in tips. Police said they have 1,400 credible leads but refused to disclose details.

Many Tasker parents kept their children home Tuesday; attendance was down by one-third. Other parents served as volunteer guards, watching over intersections.

Less than a mile from Tasker, the playground equipment at the Cresthill Baptist Church nursery school went unused. School director Stacie Hall decided to keep her 2- to 6-year-old charges indoors all day, and let the teachers choose their own gentle explanations.

Her daughter, Krystle, 13, attends Tasker and was a friend of the wounded boy. Hall said she didn't want her daughter to go to school Tuesday, but Krystle decided otherwise.

"She insisted," Hall said. "After much prayer and thought, she decided it was really important to go."

The sniper has shot eight people altogether in the past week, including one woman wounded 50 miles away in Virginia. One death occurred on a Washington street; the others came within five miles of each other in Maryland's Montgomery County. Police believe the sniper is picking victims at random and firing from a distance with a high-powered hunting or military-style rifle. All the victims were cut down by a single bullet.

Authorities said they were looking at a number of earlier shootings for possible links.

Among the cases is a Sept. 14 shooting outside a liquor store in Montgomery County that wounded a store employee.

Arnie Zelkovitz, the owner of Hillandale Beer and Wine, said police interviewed him about the shooting. His 22-year-old employee was shot in the back.

Zelkovitz said he believes his employee was a victim of the sniper: "It just seems too coincidental."

Ballistics tests found that the bullet that struck the boy was identical to those that killed some of the others and wounded a woman in Virginia. That woman was released from the hospital Tuesday.

The FBI has set up command posts in Montgomery County and provided helicopter, field office, lab and computer support. The reward posted for helping catch the sniper has increased steadily to $237,000.

At a mall near Tasker, employees at a Coldwell Banker real estate office noticed shoppers were edgy.

"They don't get out of their car without looking around, then they dash in the store," Polly Rogers said. "You don't see people on their porch, or playing tennis. We're not used to this -- we think Bowie is the safest place."