Dennis Rader, better known as the BTK serial killer, was given the harshest sentence available – 175 years without possibility of parole – for 10 murders he confessed to committing between 1974 and 1991. Today he entered the maximum security El Dorado Correctional Facility in Kansas to begin serving time.

Judge Gregory Waller issued the sentence of 10 consecutive life terms. The death sentence was not an option because Kansas had no death penalty when the murders were committed.

Rader, 60, a former church congregation president and Boy Scout leader, was arrested in February. He pleaded guilty in June to the 10 murders. During his two-day hearing, Rader apologized to his family and victims for lying to them and said he hoped the victims’ families could one day forgive him.

Rader remained anonymous throughout the years, calling himself “BTK” for “bind, torture, kill,” referencing what he did to his victims. Evidence, including journals and drawings, shows Rader carried out these murders to live out his sexual fantasies. Police say he meticulously documented the events so he could relive them later, sometimes wearing clothing from his victims to enhance the experience.

Rader will be evaluated over two weeks to determine whether he will stay at El Dorado prison or be transferred to another state maximum-security facility in Lansing or Hutchinson. The decision will be made based on whether Rader’s safety is at risk or if he appears to pose a threat to others.