ORANGEBURG, S.C. — Two young boys were pulled dead from the child seats in their car in a river and a South Carolina sheriff said this morning he expects to press murder charges against their mother.

Speaking on CBS' "Early Show," Orangeburg County Sheriff Larry Williams said there were inconsistencies in the mother's account that she'd been in an accident, such as her clothes being dry.

"For someone who had just plunged into the Edisto River here, of course, and had two children in the car, her clothing wasn't damp," Williams said of Shaquan Duley's initial report.

The sheriff also noted that Duley, 29, walked some distance from the car to find help when there were nearby houses.

Williams said investigators were ready to present their case to a judge in hopes of getting murder charges against Duley.

Duley was arrested Monday and is being held on a charge of leaving the scene of an accident after her two sons were found dead in a vehicle in the North Edisto River, still strapped into their car seats.

Autopsies are planned for today on the bodies of 2-year-old Devean C. Duley and 18-month-old Ja'van T. Duley.

Williams planned a news conference for 10 a.m. today to discuss more details.