(CNN) -- Suspected killer Marine Cpl. Cesar Laurean is most likely in Mexico, authorities said, and the prosecutor said he has agreed not to seek the death penalty if Laurean is arrested in that country.

Marine Cpl. Cesar Laurean, wanted for murder, may have fled to his native Mexico.

Onslow County, North Carolina, District Attorney Dewey Hudson told CNN that he was shown "strongly compelling evidence" compiled by federal authorities that shows Laurean is in Mexico.

Hudson said he has asked through the State Department that Laurean be arrested if he is found in Mexico. But, he said, he had "no other option" but to take the death penalty off the table if Laurean is found there.

Mexico has a longstanding record of refusing to extradite suspects to the United States if they face a possible death sentence if convicted.

"I had to agree not to seek the death penalty," Hudson told CNN. "My hands were tied if I wanted to bring him here to face murder charges."

"It was very frustrating and disappointing," Hudson added.

Laurean has been charged with murder in the death of Lance Cpl. Maria Lauterbach. Her charred remains were found January 11 in a fire pit in Laurean's backyard.

Investigators found the body after Laurean's wife came forward with a note her husband had written saying he had buried Lauterbach, who was eight months pregnant, after she slit her own throat during an argument.

Hudson said Laurean apparently entered his native Mexico only days after leaving behind that note.

Hudson would not elaborate on the evidence suggesting Laurean is in Mexico, which he said he viewed Friday. The FBI would not comment on what evidence it might have that Laurean is across the border.

"We strongly suspect, but have not confirmed, he is in Mexico," FBI spokesman Newsom Summerlin.

Summerlin said the FBI plans to circulate in Mexico either matchbooks or business cards with Laurean's photo. The Marine's wanted poster is on the FBI's Most Wanted List with a $25,000 reward.

Police believe Lauterbach was killed December 14, the same day she bought a bus ticket for travel for the following day. But in the note provided to police by Laurean's wife, the corporal claimed Lauterbach killed herself December 15.

Police said an autopsy revealed the pregnant Marine was killed by a blow to the head. Police said they are analyzing a possible murder weapon provided by an undisclosed witness. A spokesman told CNN it could several weeks to determine whether it was used to kill Lauterbach.

Laurean's wife told police about the note January 11, a day after she said Laurean told her what allegedly happened and following a meeting with a lawyer. Police describe her as a cooperating witness.

Lauterbach was scheduled to testify last month at a military hearing after accusing Laurean of raping her last spring.

On Monday, the Onslow County sheriff's office released new photographs of the fire pit in Lauren's backyard taken just before Lauterbach's body was discovered January 11. Police said some neighbors reported seeing a group of Marines having a Christmas Day barbecue in Laurean's backyard.

Police also released photographs that show Laurean's living room and garage with paint cans. Investigators said they found blood in more than one room of Laurean's home, some of which was covered by fresh paint.

The sheriff's office said it has documented evidence Laurean bought paint, concrete blocks and a wheelbarrow at a home improvement store December 16. In a store surveillance video, Laurean is seen walking into the store with another man, who has not been identified.

Investigators are also awaiting the results of DNA paternity tests, which they said could take weeks, to tell whether Laurean was the father of Lauterbach's unborn child. E-mail to a friend

All About Mexico • Federal Bureau of Investigation • U.S. Marine Corps