Updated

North Carolina authorities issued a warrant Saturday for Marine Cpl. Cesar Armando Laurean, 21, for the first degree murder of an eight-months-pregnant fellow Marine.

Authorities excavated what they believed to be the remains of Lance Cpl. Maria Frances Lauterbach from the suspect's backyard.

Click here to see photos from the case.

"That process did produce what we expected it to produce. At the bottom of that cavity, which we now call a shallow grave, were the remains of an adult and a fetus," Onslow County Sheriff Ed Brown said at an afternoon press conference in Jacksonville, N.C.

The 20-year-old woman disappeared back in December, just days after meeting with military prosecutors to discuss allegations that Laurean had raped her.

Though the remains had not yet been identified conclusively as that of Lauterbach and her unborn child, Brown said the location of the baby's remains, as well as its development, were consistent with those of a pregnant woman.

"What will stay with me for a long time is that little hand from the fetus," he said. "It is bizarre. It is tragic. It is disgusting."

Brown characterized the death as a "murder," and urged anyone with information in the case to contact police. He also said he was working with Laurean's friends to locate him.

"I want Mr. Laurean to know that we ain’t going away," Brown said in an interview on FOX News Channel. "Either he’s coming to us or we’re going to him."

The warrant for Laurean's arrest included one count of murder; in North Carolina, the killing of an unborn child does not constitute murder. If medical experts later show the child was born alive and then killed, the state will review the charges, Onslow County District Attorney Dewey Hudson said at the press conference.

Hudson also said he spoke to the Lauterbach family, and promised them he will do all he can do to make sure that justice is served.

Authorities found the burnt human remains outside the Laurean home, buried up to a foot in ashes and dirt, said Dr. Charles Garrett, the county medical examiner. They were sent to the state medical examiner's office in Chapel Hill for identification using dental records.

Investigators also found blood spattered on the ceiling and a massive amount of blood on the wall of the Laurean's home, according to Brown. It appeared someone had tried to wash and paint over the blood, he said.

A nationwide search for Laurean continued Saturday, a day after Brown identified him as the key suspect in the death of Lauterbach.

Before fleeing Jacksonville early Friday, Laurean left a note saying Lauterbach had "come to his residence and cut her (own) throat," Brown said. He confirmed that authorities had received the note from Laurean's wife, Christina, around 8 a.m. Friday, about four hours after they believe the suspect fled. But Brown also said: "That didn’t happen that way."

Laurean wrote in the note that he had nothing to do with Lauterbach's suicide, but that he had buried her body, the sheriff said.

Authorities have dismissed the idea that Lauterbach killed herself, pointing to the blood stains and the obvious signs of a cleanup inside Laurean's one-story, brown brick ranch home.

Brown declined to say whether authorities thought Christina Laurean had a hand in Lauterbach's disappearance.

She is "heartbroken," said her mother, Debbie Sue Shifflet.

"I feel sorry for the other family," Shifflet said. "It's horrible what they're going through. My heart goes out to them."

Brown concurred, appealing to Laurean and then to his family to help authorities by disclosing any information they may have. "If Mr. Laurean is listening, come tell me your side of the story," he said.

"To the family I want to say that I hate that this has happened. … Their cooperation can’t hurt their son."

Lauterbach met with military prosecutors last month to discuss pursuing rape charges against Laurean, said Kevin Marks, supervisory agent with the Naval Criminal Investigative Service at Camp Lejeune. He said military prosecutors believed they had enough evidence to argue that the case should go to trial.

In court papers filed this week, prosecutors said the anticipated birth of the baby "might provide evidentiary credence to charges she lodged with military authorities that she was sexually assaulted." Lauterbach reported the rape in April and was due to give birth in mid-February, authorities said.

Outside the family's home in Vandalia, Ohio, on Friday night, Lauterbach's uncle, Pete Steiner, said the rapist was the father.

Authorities said they had not been concerned that Laurean would flee because they had information he and Lauterbach carried on a "friendly relationship" even after she reported the assault to military authorities. There is no indication Lauterbach asked the military to protect her after she leveled the rape allegations, investigators said.

Steiner, however, said his niece didn't have any kind of relationship with her attacker, and that Lauterbach had been forced to rent a room off base because of harassment at Camp Lejeune.

"She was raped," Steiner said. "The Marines, unfortunately, did not protect her, and now she's dead."

Originally from Dayton, Ohio, Lauterbach was reported missing Dec. 19 by her mother, who last spoke with her daughter on Dec. 14, authorities said. Her cell phone was found Dec. 20 near the main gate at Camp Lejeune, and she missed a Dec. 26 prenatal care appointment.

Lauterbach, who joined the Marines in 2006, and Laurean were personnel clerks in the 2nd Marine Logistics Group of the II Marine Expeditionary Force, based at Camp Lejeune. Neither had been sent to Iraq or Afghanistan.

The Associated Press contributed to this report.