After scrutinizing a variety of electronic phone logs, Maryland State Police believe they have pinpointed the first caller who led investigators to the sleeping sniper suspects on the night of their arrests in October.

"That person wanted to remain anonymous, but apparently that can no longer be the case," said Maj. Greg Shipley, spokesman for the state police. He said he was irked by news reports yesterday that identified the tipster as Whitney Donahue of Greencastle, Pa.

The news may discount the contention of a Kentucky trucker, Ronald Lantz, 61, that he was the one to lead police to the suspects, who were parked in their car at a wooded rest stop along an interstate in Frederick County.

"We do not, at the Frederick County barracks, on 911 or even on #77 [the emergency number for cell-phone calls] have any calls that appear to come from Mr. Lantz," Shipley said. "Might he have called? I can't say for sure he didn't call. He's not a name that we have."

The first call on the sighting that came to state police in the early morning went like this: "The 1990 blue Caprice that you all are looking for, it's in a rest area, Route 70 westbound. It looks like there's two people sitting in the car." The voice in the 911 recording was Donahue's, Shipley said.

Police responding to that call found John Allen Muhammad, 42, and Lee Boyd Malvo, 17, the pair accused of shooting 13 people -- 10 fatally -- in Maryland, Virginia and the District.

Later that morning, after the predawn arrest, Lantz described his call to police in front of television cameras. He appeared on NBC's "Today" show and detailed the way he and another trucker blocked the rest stop exits while the SWAT team crept into place. He said he would share the reward money with the families of the snipers' victims.

Shipley said that there were several truck drivers who were searched, questioned and then asked to help, and that Lantz may well have been among them.

"Nobody is saying Mr. Lantz wasn't there," he said.

Both Lantz and Donahue now have unlisted telephone numbers and could not be reached for comment.

The debate over cell phone records and phone logs could be a half-million dollar question. There is $500,000 in reward money waiting to be distributed among the tipsters who gave police many pieces to the puzzle. The money probably will not be released until after Muhammad and Malvo stand trial.

Trucker Ronald Lantz claimed to have called police to the rest area along Interstate 70.Whitney Donahue made the first known call pointing out the suspects' blue Chevrolet Caprice.