Investigators looking into the killings of 10 women in the St. Louis area have accused a paroled robber in two of the killings after tracking him using the Internet.

The man, Maury Troy Travis, 36, was arrested on Friday. A federal complaint unsealed today said investigators traced him through a letter and map sent last month to The St. Louis Post-Dispatch that led the authorities to a woman's body in a remote area of suburban St. Charles County.

The complaint, filed on Friday in Federal District Court in East St. Louis, Ill., accused Mr. Travis, of Ferguson, Mo., of kidnapping, torturing and killing two prostitutes, Alysia Greenwade and Betty James.

Ms. Greenwade's body was found on April 1, 2001; Ms. James's was found in St. Louis two months later.