A 27-year-old man Upper Marlboro-area man suspected in last year's two mother-daughter slayings is also responsible for a fifth killing in what Prince George's County police are predicting will be one of the most notorious cases in the area's history.

Police have not identified the man, who is behind bars on unrelated charges, including carjacking and production of child pornography, but they say he is also a suspect in the 2008 death of Vilma Butler, a 46-year-old whose body was destroyed in a burned house in Bowie.

Prince George's County Police Chief Roberto Hylton told ABC 7 News that the suspect will go down as "one of America's most notorious criminals." Police say the person is believed to have killed Delores and Ebony DeWitt and Karen and Karissa Lofton.

- Scott McCabe