SAN ANTONIO, Texas -- Remains believed to be those of a missing Pearland man were found in a shallow grave in San Antonio, KPRC Local 2 reported Saturday.

Kenneth L. Cummings Jr., 46, was reported missing on June 8 after he did not show up for work.

Investigators have not positively identified the remains, but said they believe that they are Cummings.

The remains were buried on property belonging to the grandfather of Terry Mark Mangum, 26, who has been charged with Cummings' murder.

Texas EquuSearch volunteers found the grave not far from the roadway.

"We knew he couldn't be too far off the road because he had a 1992 Toyota. It wasn't like he had a four-wheel-drive vehicle that he could just go anywhere, so that cut down our search area," said Tim Miller with Texas EquuSearch.

Investigators said Mangum's purchases with Cummings' credit card led them to a gas station less than 16 miles from the grave site. They said he bought lighter fluid and charcoal.

Although Mangum has not confessed to murdering Cummings, investigators said he admitted to someone that he stabbed the flight attendant.

Murder is a first-degree felony, and if found guilty, Mangum faces imprisonment for life or five to 99 years and a fine up to $10,000.

Mangum is behind bars in Brazoria County with his bond set at $300,000.