Kevin George Scott, the 17-year-old Washington youth suspected of murdering one Silver Spring woman and wounding a second during robberies in recent weeks, had admitted involvement in another Siver Spring robbery last fall and had been placed on probation by Montgomery County Juvenile Court.

A source familiar with the case said yesterday Scott was scheduled to appear in Juvenile Court next Monday for violating the terms of that probation by skipping school and failing to show up for meetings with his probation officer.

Scott's plea that he was "involved" in the fall robbery had resulted in the probation pending final disposition to the case Aug. 15.

Scott's probation officer had no comment.

"Involved" is the plea the Juvenile Court accepts instead of "guilty."

Details of the fall robbery in which Scott is accused were not available yesterday.

Scott was ordered held without bond yesterday by Judge Calvin R. Sanders in Montgomery County District Court on charges of murdering Rose Blanco, 68, of 2301 East-West Hwy. as she washed her living room window May 31 and with the armed robbery of Louise McKenna, 61, of 2009 Grace Church Rd. last Friday night.

Mrs. McKenna was shot twice in the head in robbery at her home, police reported. Robbery was the motive in both incidents police said.

Judge Sanders said he based his decision to hold Scott wihout bond partly on the fact that there were "other (court) matters" involving the youth.

The question of Scott's prior record came up when the judge asked if he was on bond in anu other criminal matter. Montgomery County public defender James J. McKenna, who rep- resented Scott, and Assistant State's Attorney Michael Mason conferred with the judge at the bench, discussing information that the judge said later "by law may not be publicly divulged."

In asking for a "reasonably high bond," Mason told the judge there was some indication that Scott used drugs. A bond report made out in D.C. Superior Court, where Scott waived extradition yesterday, also indicated the youth had used drugs.

Scott, described by neighbors in the affluent North Portal area of the city as a typical tenn-ager and by his high school principal as "a nice young man," was told by the judge tthat he could receive up to life imprisonment if convicted of murder and that the maximum penalty for armed robbery is 20 years.

Scott, a senior at Coolidge High School, was not permitted to graduate last Friday - the same day as the McKenna shooting - because he had failed a chemistry course, according to shcool principal Otis Thompson.

Thompson said he had a meeting with Scott and his parents about two months ago to discuss the youth's frequent truancy.