A Donovan link in mob violence?

Law enforcement officials investigating the scattered mob violence here in the past week are faced with an unusual question: Were the shootings in any way linked to a new federal probe of US Labor Secretary Raymond J. Donovan?

Last Wednesday William P. Masselli, the son of a reputed organized-crime figure, was slain in the Bronx. Leon Silverman, the special prosecutor appointed to investigate allegations against Mr. Donovan, asked that the FBI investigate possible links between this slaying and the reopened Donovan investigation.Both Massellis had been questioned in an earlier phase of the investigation.

This week two other mob figures were shot in New York. But so far, Monitor correspondent Ward Morehouse III reports, a special task force comprising local police and FBI officials has found nothing connecting these crimes to the Masselli shooting.

On June 28 Mr. Silverman concluded that there was ''insufficent evidence'' to substantiate charges that Donovan had close business and social ties to underworld figures.

Since then, however, the special prosecutor has requested that a new grand jury be convened to examine three new allegations against the labor secretary, allegations Mr. Silverman declined to disclose.

Secretary Donovan, meanwhile, acknowledged that he had been questioned anew by Mr. Silverman and restated his conviction that he would be fully cleared.