Upon sentencing, Dahmer was transferred to the Columbia Correctional Institution. For the first year of his incarceration, Dahmer was placed in solitary confinement due to concerns for his physical safety should he come into contact with fellow inmates. With Dahmer's consent, after one year in solitary confinement, he was transferred to a less secure unit, where he was assigned a two-hour daily work detail cleaning the toilet block. Shortly after completing his lengthy confessions in 1991, Dahmer had requested to Detective Murphy that he be given a copy of the Bible. This request was granted and Dahmer gradually devoted himself to Christianity and became a born-again Christian. On his father's urging, he also read creationist books from the Institute for Creation Research. In May 1994, Dahmer was baptized by Roy Ratcliff, a minister in the Church of Christ and a graduate of Oklahoma Christian University, in the prison whirlpool.