A Fort Bragg soldier was arraigned Wednesday on first-degree murder charges in the death of a colleague who North Carolina police say was pregnant with his unborn baby.

Army Sgt. Edgar Patino, 27, told Cumberland County, N.C., Judge Laura Devane that he understood the charges against him and would ask that the court appoint him an attorney.

Patino appeared wearing an orange prison jumpsuit, his hands cuffed in front of him. Devane set his next hearing for Aug. 20.

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Earlier Wednesday, police in Fayetteville, N.C., said they zeroed in on Patino after gathering evidence that he wrote a letter to a local newspaper claiming he killed Army Spc. Megan L. Touma, whose decomposing body was found in a motel bathtub.

The note was from a person who said he was a serial killer responsible for Touma's death and featured a circle-and-cross drawing that had also been etched in lipstick on the motel room mirror where Touma's body was found.

It was the same symbol as one used a generation ago by San Francisco's infamous Zodiac Killer.

Police believe the note was written to mislead detectives and the media. Fayetteville Sgt. Chris Corcione said Wednesday that Patino wrote and mailed the letter "with the intent of throwing off investigators."

ON THE SCENE: Reaction to Arrest in Megan Touma Case

Det. Joshua Carter said that though Patino has not admitted to killing Touma, who police say was seven months pregnant with his child, "we have evidence linking the suspect with the letter" to the Fayetteville Observer.

Among that evidence is a typewriter taken from Patino's residence that investigators say was used to compose the note, Carter told reporters Wednesday. Patino allegedly purchased the typewriter the day before the letter was mailed.

Patino of Hope Mills, N.C., is being held without bond since his arrest at his home Tuesday night. He was arraigned at 2:30 p.m. Wednesday.

Authorities said he is married, which Touma only learned shortly before her death, and admitted to fathering her unborn baby.

Patino also acknowledged being in Touma's hotel room June 13, the last day her hotel room key was used, police said.

Authorities charged Patino with first-degree murder after they took him into custody without incident about 8 p.m., but did not release a motive.

"Right now, the motive is going to be held close due to the fact that this is an ongoing investigation," Carter said.

Touma, 23, was found dead June 21 at a Fayetteville motel after a maintenance supervisor smelled a foul odor coming from a room with a "Do Not Disturb" sign. A dental specialist from Cold Spring, Ky., Touma was seven months pregnant and had recently arrived from a base in Germany.

Fayetteville Police Chief Tom Bergamine said Patino is based at the John F. Kennedy Special Warfare Center and School at Fort Bragg, a Special Forces training facility.

Touma's manner of death was ruled a homicide, but a cause of death still has not been released. It will be made public at a later time by the medical examiner, police said Wednesday.

Touma's partially decomposed body was found in a motel bathtub more than a month ago. She had been dead since some time between June 13 and June 14, authorities said.

She was temporarily assigned to Fort Bragg's 19th Replacement Company, and would have eventually been assigned to work at a base dental clinic.

Touma was last seen alive not long after she arrived on June 12 at Fort Bragg in North Carolina, home to the Army's 82nd Airborne Division and its Special Operations Command. She was divorced and authorities have said nothing about the father of her child.

Police have said a Fort Bragg soldier studying psychological operations was a person of interest in the case. They said the person was training at a school where special operations ranging from raids to reconstruction projects are taught. It wasn't immediately clear if police were referring to Patino.

Touma is among three servicewomen killed in recent months near North Carolina military bases.

Earlier this month, Army 2nd Lt. Holley Wimunc, 24, was found dead in a wooded area near Camp Lejeune three days after a suspicious fire at her Fayetteville apartment. Her estranged husband, Marine Cpl. John Wimunc, who is stationed at Camp Lejeune, has been charged in her death.

In January, the burned body of Lance Cpl. Maria Lauterbach, 20, who was eight months pregnant, was discovered in a shallow grave near Camp Lejeune in the back yard of her former co-worker and a man she accused of rape, Cpl. Cesar Laurean. Laurean fled to Mexico but was arrested April 10. He has been charged with murder and is awaiting extradition.

Click here for more on this story from FOX affiliate WRAL-TV in Raleigh.

The Associated Press contributed to this report.