In the wake of pressure from Capitol Hill, D.C. Mayor Marion Barry yesterday proposed revisions in the city's pretrial detention law designed to make it easier to keep repeat offenders, particularly those accused of violent crimes, in jail until their trials.

Meanwhile, City Council member David A. Clarke (D-Ward 1), who last year introduced legislation containing most of the elements of the mayor's plan, yesterday proposed setting up a commission to draw up guidelines for sentencing criminals in D.C. courts.

The two announcements, both by officials seeking election this fall, were the latest developments in a flurry of District Building activity around the issue of crime--and keeping criminals in jail. Barry is running for reelection, while Clarke is seeking election as council chairman.

Barry said his pretrial detention bill will be introduced at today's City Council session as emergency legislation. With the exception of two new provisions, it is virtually identical to legislation approved by Clarke's judiciary committee last week and originally introduced by Clarke last year.

The new focus on pretrial detention comes after Sen. Alfonse D'Amato (R-N.Y.), chairman of a key Senate subcommittee that holds the District's purse strings, urged officials to crack down on repeat offenders, and particularly to use any means to keep violent offenders from being released on bail after new arrests.

D'Amato had suggested that the city impose high cash bonds in the case of repeat offenders--a measure questioned by Clarke's committee, among others, as potentially unconstitutional. The bill Barry announced yesterday contained no provision for high cash bonds.

Barry's proposal would allow authorities to detain for three days suspects charged with serious crimes who were, at the time of arrest, free on bond in connection with another pending case.

Barry, with Police Chief Maurice T. Turner at his side, said the three-day hold would give judges a chance to reconsider the suspect's original conditions of release, and possibly order that the suspect be held.

The mayor's bill also would permit authorities to investigate the sources of property suspects use as collateral to secure release. If it is found that the property was obtained by illegal means, such as drug sales, Barry said, the judge could refuse to accept it and the suspect would remain in jail.

In addition, Barry's bill contains provisions, also contained in Clarke's pretrial detention bill, that would extend from 60 to 90 days the period a suspect could be held in pretrial detention; suspend the 90-day limit in first-degree murder cases; and increase from five calendar days to five working days the maximum time authorities could hold a suspect while seeking to determine whether he had violated probation or parole.

"We think this is going to help stop the revolving-door situation where one person is arrested for multi-offenses, out on personal recognizance, third party custody, arrested again, out on personal recognizance . . . ," Barry said.

Asked why he had not proposed such legislation earlier, Barry attempted to shift much of the blame to the council, saying the problem was "more legislative."

Emergency legislation, after being approved by the council and signed by the mayor, becomes effective immediately for 90 days. Meanwhile, an identical bill is moved through the council's much more lengthy procedure so it may become permanent legislation when the emergency measure expires.

Clarke's sentencing bill, which will be scheduled for public hearings and council action later in the year, would create a 10-member commission to first compile and examine local sentencing practices and then develop guidelines for the 44 D.C. Superior Court judges.

Clarke, who opposes mandatory minimum sentencing as too restrictive, said judges would be required to follow guidelines specifying "a relatively small range of sentences" for specific crimes, unless the judge placed on the record "specific findings of fact and reasoning for deviating" from the guidelines.

The bill sets forth a list of aggravating and mitigating factors the judges may consider.

Clarke said that currently a defendant, depending on the judge and the crime, can receive no sentence or terms up to life imprisonment. He aid such variances are "engendering disrespect within both the general population and the imprisoned population."

The commission would consist of three Superior Court judges, the director of the Department of Corrections, a defense attorney, one member appointed by the U.S. attorney and four from the public at large.

Similar commissions have been established in other jurisdictions, Clarke said, including Utah, Minnesota and New Jersey.