He wrote two books on the Oklahoma City bombing based on knowledge gleaned first-hand from Timothy McVeigh before McVeigh's execution: Secrets Worth Dying For: Timothy James McVeigh and the Oklahoma City Bombing (2004), co-authored with Jeffery William Paul. Later in 2010, Hammer published Deadly Secrets: Timothy McVeigh and the Oklahoma City Bombing. In May 2010, shortly following Deadly Secrets’ publication, Hammer appeared on Alex Jones’ talk show for an extended interview, detailing his relationship with McVeigh and McVeigh's account of the US government's alleged involvement in the bombing. On February 11, 2004, Hammer's third execution date was set for June 8, 2004. The Appellate Court stayed Hammer's execution only 4 days before June 8th to allow for review of his case. On December 27, 2005, the district court vacated Hammer's death sentence and set aside his conviction based upon the government hiding favorable evidence that supported Hammer's defenses. Back in court, on July 17, 2014, U.S. District Judge Joel Slomsky resentenced Hammer to life imprisonment without possibility of parole. Judge Slomsky found multiple circumstances warranting a sentence less than death, including Hammer's acceptance of responsibility and remorsefulness, his extended family history of dysfunction, abuse and mental illness, his mental and emotional impairments, and his self-improvement. Judge Slomsky also identified Hammer's medical diagnoses - “diabetes mellitus, type II [high blood sugar requiring insulin dependency], diabetic polyneuropathy [the gradual destruction of nerve sensations, especially in the extremities], diabetic retinopathy [scarring of the retina], and/or diabetic macular edema [release of retinal blood into the vitreous fluid in the eye, blocking vision to the point of legal blindness]” - and Hammer's charitable contributions during his 9 years on death row and his correspondence with at-risk children counseling them against engaging in criminal conduct. At the time of his resentencing, Hammer had long been classified as a BOP Medical Care Level 3 inmate. In early 2015, after 18 years in solitary confinement, BOP transferred Hammer directly to USP-Tucson, one of the few BOP prisons able to accept Care Level 3 inmates. Within a few months, they hospitalized Hammer for a partial amputation of his right foot for osteomyelitis, a bone infection. The amputation did not cure his condition, and BOP reclassified him to a Care Level 4.