Tougher sentencing laws have succeeded in increasing the length of time criminals serve in prison and have slowed the release of inmates, concludes a new Justice Department study. One effect has been an increase in the prison population in the United States -- including those in local jails, a record 1.8 million persons are behind bars.

According to the report prepared by the Bureau of Justice Statistics:

• The average time served in state prison by violent criminals rose to 49 months in 1997 from 43 months in 1993.

• Measured another way, the proportion of their sentences these offenders had to serve before release grew to 54 percent in 1997 from 47 percent in 1993.

• Also, the number of all types of criminals eligible for release from state prison who were actually let out fell to 31 percent in 1996 from 37 percent in 1990.

The increase in time spent in prison occurred at the same time crime rates were falling. The number of arrests for murder, for example, declined to 16,100 in 1996 from 19,800 in 1990. However, the rate at which murderers were sent to prison rose to 613 per 1,000 arrests in 1996 from only 460 per 1,000 arrests in 1990.

The Justice Department report suggests the movement by the states and the federal government, beginning in 1984, to pass so-called truth-in-sentencing laws has been a factor in increasing the length of time served.

Sources: Paula M. Ditton and Doris James Wilson, "Truth in Sentencing in State Prisons," Special Report, January 1999, Bureau of Justice Statistics, Washington D.C.; Fox Butterfield, "Inmates Serving More Time, Justice Department Reports," New York Times, January 11, 1999.

For text http://www.ojp.usdoj.gov/bjs/pub/ascii/tssp.txt