It was the second time in six months that a pregnant, unwed servicewoman in North Carolina was slain and a comrade fell under suspicion. In December, Lance Cpl. Maria Lauterbach, a 20-year-old clerk based at Camp Lejeune, was killed, and a fellow Marine was captured after fleeing to Mexico. Both victims were just weeks away from giving birth.

Detectives in the Touma case said the letter may, in fact, have come from the killer. The writing on the mirror was not public knowledge until The Fayetteville Observer published that detail over the weekend along with the contents of the letter. But investigators do not believe the author's claim to be a serial killer.

"We just believe that it was merely a tactic used to divert us off of what we are doing, and to cause panic in the community, which we have to deal with, too," Sportsman said. "But we don't believe there's a serial killer in Fayetteville."

Touma, who was from Cold Spring, Ky., was a dental specialist from a military family who joined the Army in 2003. Seven months pregnant, she had recently completed a three-year tour in Germany. She was last seen alive not long after she arrived on June 12 at Fort Bragg, home to the Army's 82nd Airborne Division and its Special Operations Command.

She was divorced. Authorities have said nothing about the father of her child.

Maintenance man noticed foul odor
Her body was found by a maintenance man at an off-base motel on June 21. He entered the room, protected for four days by a "Do Not Disturb" sign, and noticed a foul odor. Among the items investigators removed were sections of drywall stained with what might be blood, according to court papers.

The Observer published the letter after holding back for three days at the request of Fayetteville police. The newspaper, citing unidentified sources, said the marking on the mirror inside Room 143 was made with lipstick and was identical to the symbol in the letter. Officially, police will say only that the symbols were similar.

The letter writer taunted Fayetteville law enforcement authorities as "very incompetent. I basically, sat there and watch while investigators were on site."

The Zodiac killer was blamed for at least five slayings in California in the late 1960s but never caught.

Fayetteville detectives and Army investigators were compiling evidence Tuesday and awaiting the results of a military autopsy on Touma. The details of an earlier autopsy done by civilian authorities have not been released.

"We're at a critical point right now," Sportsman said. "There's a lot of things going on right now. There's a lot of evidence being processed, a lot of interviews. It's just a matter of time."