Maness is a 20-year retired Texas Department of Criminal Justice senior clinical chaplain, life member of the American Correctional Chaplains Association, and the author of over 11 books and 100 articles, including several exposés, including the Book of Secrets on the Longest Cover Up in TDCJ History (2013) and the TDCJ Deep State Report (2019).
He successfully lobbied in Austin for state chaplains three times, the first in 2001 that won the first group pay increase in 40-plus years for state chaplains. In 2007, he led the effort that won back 25 of the 50 chaplain jobs that were cut by TDCJ in 2003. When TDCJ killed the chaplaincy in the 2011 budget, he led the effort in Austin that won back the entire chaplaincy budget, that history recorded in How We Saved Texas Prison Chaplaincy 2011 (2015) with four forewords, including then Texas House Corrections Committee Chairman Jerry Madden.
Maness spent 20 years as the senior chaplain of the Gib Lewis State Prison in Woodville, Texas, that housed over 2,300 minimum, medium, and high security prisoners. He has facilitated the religious needs of all the major faiths and a host of others and over 100 fantastic religious volunteers. Maness facilitated over 5,000 death and critical illness messages and earned a host of certificates and awards for training after earning a M.Div. from SWBTS and a D.Min. from NOBTS, with a dissertation that proved that prisoners could learn the basic skills of empathy.
In the 1990s, he wrote the first Prison Volunteer Handbook that was used by several prisons until TDCJ developed its own manual which utilized much the same information.
His website, PreciousHeart.net, has one the largest archives on prison chaplaincy in the world and the largest in Texas.