PASADENA, Texas -

Pasadena police say they have solved the cold case murders of a mother and her son from nearly 30 years ago.

Back in 1985, William Roger Hancock was initially charged with the murder of a 12-year-old boy and his mother, but a grand jury elected not to indict him. Investigators Wednesday made contact with Hancock in the Polunsky Unit of the Texas Department of Criminal Justice in Livingston where he is serving time for sexual assault.

During an interview, investigators say Hancock confessed to and provided detailed descriptions of the 1985 murders of Charley Boring III and Kathenia Anita Willems. The cause of death for both victims was asphyxiation by ligature.

Hancock, 56, is now charged with two counts of capital murder/kidnapping.