There are specific state and federal laws that define, prohibit, and penalize criminal behavior. Various factors, such as the nature and type of the crime committed and the relevant law, may determine whether the state or federal justice system is responsible for the prosecution, sentencing, and incarceration of an individual accused and found guilty of a crime. State and federal laws also define the potential sentences for those crimes to be imposed by judges and methods for reducing the period of incarceration, such as parole, probation, or good conduct time credit. These laws and policies affect the growth of their respective prison populations and the level of crowding in state and federal prison populations. To carry out its responsibility for the custody and care of federal offenders, BOP currently houses inmates across six geographic regions in 117 federal institutions, 15 privately managed prisons, 185 residential reentry centers, and home detention. BOP’s central office consists of eight divisions that provide oversight of major BOP program areas and operations, such as correctional programs and health services, as well as the National Institute of Corrections (NIC). BOP has six regional offices, each led by a regional director, covering the North Central, Northeast, South Central, Mid-Atlantic, Southeast, and Western regions of the United States. BOP generally houses sentenced inmates in its long-term institutions. Male long-term institutions include four security level designations–– minimum, low, medium, and high––and female institutions include three security designations––minimum, secure, and high. The security level designation of a facility depends on the level of security and staff supervision that the institution is able to provide, such as the presence of security towers; perimeter barriers; the type of inmate housing, including dormitory, cubicle, or cell-type housing; and inmate-to-staff ratio. Additionally, BOP designates some of its institutions as administrative institutions, which specifically serve inmates awaiting trial, or those with intensive medical or mental health conditions, regardless of the level of supervision these inmates require. From fiscal years 2006 through 2011, the distribution of facilities by security designation remained relatively constant. In fiscal year 2011, there were 7 stand-alone minimum security camps, 29 low security facilities, 46 medium security facilities, 16 high security facilities, and 19 administrative facilities. BOP establishes a rated capacity for each of the facilities that it owns and A facility’s rated capacity reflects the number of prisoners that operates. it was designed to house safely and securely and in which BOP can provide inmates adequate access to services, necessities for daily living, and programs designed to support their crime-free return to the community. In determining a facility’s rated capacity, BOP considers American Correctional Association (ACA) occupancy and space requirements. Since 1990, ACA has required 35 square feet of unencumbered space per inmate to ensure that each inmate has sufficient movement or exercise space within the inmate’s personal living space, whether in a cell, room, or open dormitory. In essence, rated capacity is the measure of inmate housing space and, therefore, does not include housing used for medical and special housing purposes (e.g., disciplinary segregation and administrative detention space). BOP also does not include in its rated capacity additional beds placed in areas such as a facility’s halls, gyms, mezzanines, or television rooms to address crowding. BOP excludes this use of space from its rated capacity calculation because it considers these beds to be temporarily converted housing space that is to be restored to its original purpose when circumstances permit. Further, for such temporary space to become permanent space and thus included in a facility’s rated capacity, the facility would require infrastructure changes, such as additional toilet or shower facilities, to meet ACA standards. According to BOP, rated capacity is the basis for measuring prison crowding and is essential to both managing the inmate population and BOP’s budget justifications for capital resources. BOP’s formula for calculating rated capacity has changed over time. Until 1991, the rated capacity of a facility was equivalent to the total number of cells, because the rated capacity was based on one inmate being housed in each cell. As a result of the growth in BOP’s population during the 1980s, BOP began to double-bunk (i.e., house two inmates in each cell) in many of its facilities, particularly those at the lower security levels. In 1991, BOP established a new rated capacity formula that allowed for stratified bunking across all security levels. BOP’s current rated capacity guidelines account for 25 percent double bunking and 75 percent single bunking of cells within high security facilities, 50 percent double bunking and 50 percent single bunking of cells within medium security facilities, and 100 percent double bunking of cells in low and minimum security facilities. By way of illustration, figure 1 shows crowding in a medium security facility and a high security facility, each with 20 cells. The rated capacity of the medium security facility, which includes 50 percent double bunking, is 30 beds. With a population of 45 inmates, 67 percent of the inmates are double bunked, 33 percent are triple bunked, and the facility’s percentage crowding is 50 percent. The rated capacity of the high security facility, which includes 25 percent double bunking, is 25 beds. With a population of 39 inmates, 97 percent of the inmates are double bunked, 3 percent are single bunked, and the facility’s percentage crowding is 56 percent. BOP initially classifies an inmate to a particular institution based on the level of security and supervision the inmate requires; the level of security and staff supervision the institution is able to provide; the inmate’s program needs, such as residential drug treatment or intensive medical care; where the inmate resides when sentenced; the level of crowding in an institution; and any additional security measures to ensure the protection of victims, witnesses, and the public. In most cases, BOP’s Designation and Sentence Computation Center staff calculates a point score for the inmate and then matches the inmate with a commensurate security level institution. As of December 31, 2011, BOP had a total staff of about 38,000, including correctional officers and administrative, program, and support personnel responsible for all of BOP’s activities nationwide. BOP’s philosophy is that all employees are correctional workers first, whether or not they serve as correctional officers. Accordingly, BOP trains all employees in basic correctional duties to secure the facility in the event of a disturbance and to provide inmate supervision. BOP also requires them to participate in annual refresher training. When circumstances warrant, a warden will require program and administrative staff members to serve in the capacity of a correctional officer––a practice that BOP calls augmentation. For example, under augmentation, a vocational education teacher or a psychologist may provide escort services for an inmate leaving the facility for specialized medical care or provide ancillary supervision in a recreational yard. Selected state departments of corrections included in our review share similarities and exhibit differences with BOP. For example, both state departments of corrections and BOP are required to house, clothe, and feed inmates in a safe and secure setting, but selected states determine rated capacity and measure crowding differently. Several of the selected state departments of corrections’ methods are different from BOP’s methods. For example, New York calculates rated capacity using standards set forth by the New York State Commission of Correction and by subtracting temporary beds from the number of general population beds. In contrast, Wisconsin does not calculate rated capacity but instead uses design capacity and operational capacity. Furthermore, differences in state and federal authorities affect the types of actions that are taken to mitigate the effects of crowding. For example, state departments of corrections may have been granted certain state statutory authorities that are not currently available at the federal level (i.e., states may transfer inmates to county and local jails, but BOP does not have this option). From fiscal years 2006 through 2011, the inmate population in BOP-run facilities grew 9.5 percent, while capacity grew less than 7 percent. As a result, BOP’s overall crowding increased during this period from 36 percent to 39 percent. BOP projects an additional 15 percent increase in its inmate population by 2020. The inmate population housed in BOP-run facilities steadily increased from 162,514 to 177,934 inmates—or 9.5 percent—from fiscal years 2006 through 2011. A variety of factors contribute to the size of BOP’s population. These include national crime levels, law enforcement policies, and federal sentencing laws, all of which are beyond BOP’s control. During the 6-year period, growth occurred in BOP’s male, female, and both its U.S. citizen and non-U.S. citizen populations. Specifically, The number of male inmates housed in BOP institutions increased about 10 percent (151,003 to 165,595). The number of female inmates housed in BOP institutions increased about 7 percent (11,511 to 12,339). The relative proportion of non-U.S. citizen to U.S. citizen inmates housed in BOP facilities remained constant (about 26 percent), although the approximately 16 percent (46,369 to 53,733) growth in the noncitizen inmate population surpassed the approximate 13 percent growth in the U.S. citizen inmate population (135,074 to 152,581). Non-U.S. citizen inmates are housed in BOP-run low, medium, and high security level facilities, as well as in private contract facilities. The largest number of these inmates are housed in low security facilities.