In America some 2.2 million people are behind bars, and the prisoners are getting older. The number of people over the age of 65 who were in prison has doubled since 2007. In fact, aging men and women are the most rapidly growing part of America's prison population. In part, this is the hangover effect of the 1980s and 90s when a perfect storm of high crime rates and tough sentencing laws caused prison populations to soar. Phillip Burdick is 64. He works alongside Mr Baxter in a program called the Gold Coats. The volunteer inmates who become Gold Coats are carefully screened and shadow an experienced volunteer sometimes for several months of training. Older prisoners often have special needs; some have problems with mobility, others dementia or mental health.