There's a new name on the FBI's Ten Most Wanted Fugitives list.

Authorities have added the man suspected of killing a Tennessee woman and her teenage daughter and fleeing with the woman's two other young girls, as police hope more public attention to the case will help them nab the suspect, Adam Mayes.

Earlier Wednesday, two first-degree murder charges were filed against Mayes, 35, who has been sought by authorities for more than a week. His wife, Teresa Mayes, was also charged.

His inclusion on the Most Wanted list comes with a $100,000 reward for anyone providing information leading to his arrest. Local authorities have also pitched in an additional $75,000.

An affidavit says Teresa Mayes of Guntown, Miss., told authorities she was with Adam Mayes on April 27 when he allegedly killed Jo Ann Bain, 31 and her 14-year-old daughter, Adrienne, in a garage at the Bains' Whiteville, Tenn., home.

Teresa Mayes told officials the motive was to kidnap Bain's two younger daughters, 12-year-old Alexandria and 8-year-old Kyliyah.

A call seeking comment from Teresa Mayes' attorney wasn't immediately returned.

Meanwhile, authorities released new surveillance video Tuesday they say shows Adam Mayes in a convenient store three days after the women disappeared, MyFoxMemphis.com reported.

The store clerk described Mayes as “calm” and “normal,” the station reported. He even purchased a Coke.

"I remember he had a haircut because he had a  pony(tail) and now he had a haircut," Nick Barghoutti, the clerk, said.

The FBI said Tuesday that authorities were hopeful the two young girls were still alive, but it declined to say why. Mayes may be anywhere in the U.S, the agency said, and FBI spokesman Joel Siskovic said investigators think the two girls are still with him.

Authorities have described Mayes as a family friend of the Bains', who was staying with them at the time of the family's disappearance. Before he fled, he admitted to authorities that he was the last person to see Jo Ann Bain and her daughters, according to an affidavit filed with the court.

The bodies of Jo Ann Bain and Adrienne Bain were found last week behind the mobile home in northern Mississippi where Mayes lived. The affidavit provides the first clue that the victims may have been killed soon after they were abducted. It said his wife and mother saw him digging a hole in the yard on April 27 or soon after.

Click here for more from MyFoxMemphis.com

The Associated Press contributed to this report.