Boston — One out of every 590 Americans is behind bars in federal, state, or county correctional facilities. The nation's overall inmate population, now in excess of 385,000, has doubled during the past decade.
These statistics are vexing to US public officials, where the number of prison inmates climbed a record 13.7 percent from April 1981 to last March.
The sharp increase in prisoners, generally attributed to toughening of sentencing laws and mandatory incarceration for certain serious offenses, comes at a time when most correctional facilities have long since reached or exceeded capacity.
Compounding the problem, about two-thirds of the states are already under court order to reduce prison overcrowding or upgrade inmate living conditions.
The federal government and all but three states - Montana, New Hampshire, and South Dakota - have built new correctional facilities or expanded existing ones over the past two years.
While the price tag for expanding correctional complexes varies with size and type of prison (maximum, medium, or minimum-security) as well as location, the current average cost of state facilities is $20.7 million and $6.7 million for county detention centers and local jails.
The average per-bed cost of building a correctional facility is $48,004 at state institutions and $44,533 for county and municipal jails.
Within the past year three federal correctional facilities, 35 state prisons, and 35 local jails have been completed, according to Leeann Irwin of the Washington, D.C.-based National Moratorium on Prison Construction, a project of the Unitarian Universalist Service Committee.
An April Gallup poll found that 57 percent of those queried favored building more prisons, and 49 percent were willing to pay more to have them. At the same time 76 percent endorsed the Reagan administration's proposal to turn unused military property into prisons.
Because of soaring construction and operating costs of prisons, a variety of alternatives to the prison population dilemma are being explored and developed.
Connecticut, Georgia, Illinois, Michigan, Minnesota, Oklahoma, Virginia, and others have, with varying degrees of success, at least experimented with different approaches to holding down the number of convicts held.
But programs to ease prison overcrowding are posing a new set of concerns. A report just released by the Bureau of Justice Statistics says 1.5 million Americans, or three-fourths all adults in the US correctional system, are on parole or probation. So, ironically, while many courts and state legislatures are anxious to develop alternatives to incarceration, other states are tightening parole eligibility regulations, some abolishing the provisional release system entirely.
During the past five years 37 states have enacted mandatory sentences for serious offenses including armed robbery, drug dealing, and drunken driving.
While there is considerable difference of opinion in the corrections field and lawmaking circles concerning the best solution to overcrowding, it is generally agreed that federal, state, and local governments cannot afford to build enough new prisons to house all convicts.
In Minnesota, sentencing guidelines restricting the use of incarceration to those convicted of the most serious offenses and those with criminal histories have been in effect since May l980. In the first 18 months of the law, admissions to the state's correctional system dropped nearly 20 percent.
Several states are attempting to ease overcrowding through an early-release system. One of the most extensive is in Michigan, where 1,800 prisoners have gained their freedom up to three months before expiration of their sentences. Under a 1981 law, whenever state correctional institutions exceed legal capacity for 30 consecutive days, the governor issues an emergency directive making prisoners within their last three months of imprisonment eligible for early parole. Inmate releases continue until the state's prison population drops below 95 percent.
A 1981 Connecticut law sets maximum population levels for the state's correctional system and empowers the commissioner of corrections to petition the courts for the release of inmates nearing the end of their sentences and to release some pretrial detainees.
Oklahoma in April 1980 adopted limitations on the legal capacity for each correctional facility. Under it the state Pardons and Parole Board is directed to consider for release all nonviolent offenders six months prior to the expiration of their term of incarceration. The measure bars the transfer of prisoners from overpopulated county jails to state penal institutions.
In Illinois a two-year-old ''good times'' credit arrangement permits certain inmates nearing the end of their sentences to earn their freedom up to 90 days early. Those eligible can earn a day off for each day served with good behavior, with additional time off for exemplary activities such as completion of an educational program, performance of extra work, or acts of heroism during incarceration. Under the program nearly 4,600 prisoners won early releases between June 1980 and January 1981.
The Georgia approach to overcrowding involves the post-sentencing diversion of some convicts to a type of halfway house involving supervised job training, educational assistance, and restitution to victims of the inmate's crime. Since the program began in 1975 it has expanded from a single facility to a dozen, with an average capacity of 40. Those diverted to the program by judges are prisoners convicted of offenses involving property rather than physical violence.
A somewhat different prisoner diversion setup is taking shape in Virginia under a 1980 law providing state funds to communities for establishing local supervision of persons convicted of nonviolent offenses who may require less than institutional custody but more than release on probation. Those in the program either live at home or in an assigned dwelling and are under strict supervision. They are required to make restitution to the victims of their offense, provide certain community service, and have gainful employment.
''There are many options for dealing with prison overcrowding,'' says Kay Harris, professor of criminal justice at Temple University. The former director of the Washington office of the National Center on Crime and Delinquency warns ''there is no quick fix'' or single solution appropriate to all states.