(CNN) -- A video recorded last month shows suspected Marine killer Cesar Laurean buying supplies that authorities say could have been used to cover up the murder of a pregnant co-worker, a sheriff's department spokesman told CNN on Friday.
The surveillance video from December 16 shows Cpl. Laurean shopping at a Lowe's home improvement store two days after Lance Cpl. Maria Lauterbach is believed to have been killed, said Onslow County Sheriff's spokesman Rick Sutherland.
CNN obtained the video from the television program "America's Most Wanted" and broadcast it during Friday night's "Anderson Cooper 360."
In the video, Laurean is seen with another person described by "America's Most Wanted" as "a friend." Sutherland said that investigators believe Laurean was with someone at the store, but had no other comment.
The video shows Laurean purchasing supplies, paint, concrete blocks and a wheelbarrow.
According to police affidavits, Laurean told his wife he buried Lauterbach in their backyard fire pit December 15 after Lauterbach committed suicide in the couple's home -- slitting her own throat. He said he got scared and buried her body, according to the affidavit. Watch what may have happened at the fire pit »
Police say they don't believe his version of the story. They have told CNN that they found blood in more than one room of Laurean's home and that some of the blood was covered by fresh paint. Lauterbach's charred body, as well as that believed to be of her unborn child, were found in the fire pit.
Lauterbach, 20, had accused Laurean of raping her last spring. She was reported missing December 19.
Laurean is charged with her murder. An initial autopsy report indicates Lauterbach was killed by blunt trauma to the head.
Neighbors claim to have seen Laurean's wife Christina painting the inside of her home recently, Sutherland said.
"There are some initial reports to suggest that neighbors saw Christina Laurean doing some of the interior painting done in the last month," he said.
She has not been charged in the murder case. Police told CNN she remains a cooperating witness.
Christina Laurean waited a day after her husband told her about Lauterbach's death before telling authorities about what she knew, according to police search warrant affidavits.
Police are also releasing video of Laurean withdrawing money from an ATM allegedly using Lauterbach's card on December 24. Police have said he attempted to cover the camera lens with what appears to be a rag or towel.
Authorities suspect Laurean may be on the run in the southwestern U.S. or Mexico, where some of his relatives live. Authorities received a credible tip that he has been seen in the western United States, police said.
Laurean is a naturalized U.S. citizen born in Mexico. E-mail to a friend
CNN's Tristan Smith and Chuck Hadad contributed to this report.