posted 10-22-2002 02:50 PM               

ASPEN HILL, Md. (Oct. 22) - A bus driver was shot and killed early Tuesday in an attack that bore the hallmarks of the serial sniper who has slain nine other people in the Washington area this month.

Conrad Johnson, a 35-year-old father of two, was shot as he stood at the top of the steps of the bus shortly before 6 a.m., Montgomery County police said.

The location, 15 miles north of downtown Washington, is less than a half-mile from where the rampage began Oct. 2. In all, 12 people have been confirmed shot by the sniper in Maryland, Virginia and Washington, D.C.; three were critically wounded.

''We remain concerned about the safety of all the people in our region,'' Police Chief Charles Moose said Tuesday.

''We realize that the person or the people involved in this have shown a clear willingness and ability to kill people of all ages, all races, all genders, all professions, different times, different days and different locations,'' he said.

Moose, who had used three previous briefings to communicate directly with the person he hinted was the sniper, told reporters at a midday briefing he had no new messages to relay via the media.

A senior law enforcement official speaking to The Associated Press on condition of anonymity said Tuesday a letter found near the scene of Saturday night's sniper shooting in Virginia suggested the killer wants several million dollars.

Two other law enforcement sources told the AP the letter also contained information that police interpreted to be a vague threat to children. One of the sources, who also spoke on condition of anonymity, said the letter was ''lengthy.''

Schools in the Richmond area, near Saturday's shooting, remained closed a second day Tuesday.

Immediately after Tuesday's shooting, police put a widespread dragnet into place, clogging traffic on Connecticut Avenue, one of the main arteries into Washington, just as the morning commute began.

The shooting happened near an apartment building and wooded area along Connecticut Avenue. The bus was parked at a staging area where drivers get ready for their morning runs, state police spokesman Cpl. Rob Moroney said. He didn't know if anyone else was on the bus.

Johnson, a 10-year county employee, had been taken to Suburban Hospital in Bethesda.

Agents for the federal Bureau of Alcohol, Tobacco and Firearms combed the crime scene. A police dog searched near a basketball court in a park, and police helicopters flew over the scene.

''I was getting ready to leave for work this morning. I heard a loud bang,'' said Kim Roberts, a carpenter who lives nearby. ''It wasn't a pop like a handgun. If it was a gun, it was a high-powered weapon.'' He said he knew about the sound of weapons from his military service.

Within minutes, police closed many roads around the shooting scene and set up roadblocks at points along the Capital Beltway. Teams of officers were stopping all cars driven by men, not just white minivans or box trucks which have been the focus of earlier sniper shootings. By late morning, the roadblocks were largely lifted, police said.

On Monday, the hunt turned into a case of high-stakes phone tag.

Saturday night, the sniper critically wounded a 37-year-old man outside a steakhouse in Ashland, Va. On Monday, police said they received a call about the attack, hinting it was from the sniper, but that the call was muddled.

''The person you called could not hear everything you said. The audio was unclear and we want to get it right. Call us back so that we can clearly understand,'' said Moose, who has been leading the hunt.

Moose did not disclose who received the call, when it was made or other details. But investigators believe the call may have come from the sniper and that the caller was the person who left the note and phone number at the scene of Saturday night's shooting, a law enforcement source told the AP on condition of anonymity.

The Los Angeles Times, citing unidentified federal agents, said the letter was poorly worded, bordering on broken English.

On Sunday, Moose publicly pleaded with the note writer to call authorities.

Then in the first of two televised statements Monday, the chief said: ''The message that needs to be delivered is that we are going to respond to a message that we have received. We are preparing our response at this time.''

Saturday's victim was felled by a single shot to the stomach. He remained in critical but stable condition at a Richmond hospital Tuesday after doctors removed his spleen and parts of his pancreas and stomach. Surgeons retrieved the bullet after surgery Sunday, and ballistics tests linked the slug to the ambush killer.

Moose's plea Monday came hours after Virginia authorities surrounded a white van parked near an Exxon gas station just outside Richmond and seized two men. They said later the men had no connection to the sniper.

Several newspapers reported Tuesday that the men apparently made the mistake of driving the white van up to a phone booth being watched by police. The phone booth had been traced to one that the letter writer had used.

A Justice Department official said deportation proceedings had begun against the two - a 24-year-old Mexican and 35-year-old Guatemalan.