Most deaths that occur in prison occur within a month after the inmate has been admitted into the prison facility, and suicide is the number one cause of unnatural death among all inmates.  In fact, suicide rates among prison inmates are increasing at a rate that is higher than the risk of suicide outside the prison. 

These facts come via a report called Mortality in Local Jails, 2006, 2007 by the Bureau of Justice.  According to the Report, there were 8,110 inmate deaths reported to the Deaths in Custody Reporting Program, between 2000 and 2007.  Deaths in US prisons actually increased from 905 in 2000, to 1103 in 2007.  Out of these deaths, illness accounted for approximately 53% of all prison deaths.  The number one illness that killed prison inmates was heart disease, which killed 22% of all inmates, followed by AIDS, cancer, liver disease and other illnesses.  Inmates who died of drug and alcohol intoxication accounted for approximately 7% of all inmate deaths.  3% of the inmates died in accidents, while 2% were the victims of homicide.  Another 6% died of unknown causes.

Among unnatural causes of death, suicide was the number one killer in American prisons.  A total of 2,363 prison inmates committed suicide between 2000 and 2007 in US jails, accounting for 29% of all prison deaths.  Next to illness, suicide is the number one cause of death in these prisons.  During the study period, suicide rates were much higher in small prisons than in the larger prisons.  The suicide rate was 169 per 100,000 inmates in prisons with a capacity of 50 inmates or fewer, and in larger prisons, the rate was 27 suicides per 100,000 inmates.  Suicide rates in the small jails were up to six times higher than in the larger prisons. 

Not surprisingly to Los Angeles criminal defense attorneys, males were more likely to die in prison than female inmates, and were also more likely to commit suicide in prison.  However, females were much more likely to die from alcohol intoxication.

The most interesting thing to take home from the study is the fact that suicides and not homicide - which is what the general public might assume - kills more prison inmates.  More prison inmate commit suicide than are killed by their fellow inmates, or suffer fatal heart disease or AIDS.  At the very least, the report points to a need for enhanced medical care and mental health counseling for prisoners in US jails.