Rockville (Maryland): After a bus driver was shot and killed, possibly becoming the Washington area sniper's 10th murder victim, police tried to contact the killer who now is threatening to target children and reportedly demanding a $ 10 million ransom.

"Your children are not safe anywhere at any time," said a message from the murderer read on October 22 by Montgomery County police chief Charles Moose. It was found late October 19 near the last confirmed sniper shooting in Ashland, Southern Virginia.

It was the most dramatic moment in an anxiety-packed day that began when a bus driver was gunned down as he was preparing his vehicle for service in nearby Montgomery County, Maryland.

The 35-year-old father of two was declared dead later that morning.

If confirmed by ballistic analysis, Conrad Johnson would be the 10th fatal victim of the Washington area sniper and the 13th person shot since the murder spree began October 2 not far from where Johnson fell.

Moose on October 22 once again talked directly to the sniper or people close to him via the media, saying, "We have researched the options you stated and we have determined it is not possible electronically to comply in the manner that you requested."

"However, we will remain open and ready to talk to you about the options you have mentioned."

"It is important to do this without anyone else getting hurt," Moose added.

"You have indicated that this is about more than violence," he said. "We are waiting to hear from you."

The cryptic message came in answer to a letter the sniper apparently left near the scene of his latest confirmed shooting outside a restaurant in Ashland, Southern Virginia, where a 37-year-old man was wounded.

The letter, according to law enforcement sources quoted on October 23 by 'The Washington Post' daily, was three pages-long, handwritten, wrapped in plastic and tacked to a tree.

In angry tones, the sniper complained that police dispatchers had ignored half a dozen of his calls, branding them as "incompetent", and adding that "five people had to die" because of the bungling.

It also reprimanded police saying it would be better for them to try to stop the killings rather than making an arrest.

The letter, said the sources, also included the same phrase the murderer had jotted down on a Tarot card left at the scene of an October 7 shooting: "I am God."