BALTIMORE, OCT. 4 -- The head of a Maryland Ku Klux Klan group was sentenced today in federal court to 36 months in prison after admitting he owned an illegal arsenal of 20 handguns, rifles and shotguns and conspired to possess two live hand grenades. Robert Louis White, 46, grand dragon of the Maryland Knights of the Ku Klux Klan, also faces a possible three-year sentence this week in Baltimore Circuit Court for assaulting a black man in a racial brawl last March. A former Baltimore police officer, White also was convicted in 1981 of conspiracy to bomb a synagogue. At today's sentencing in federal court, White's attorney, Leonard S. Freedman, said the Klan leader seemed to have "mellowed considerably" after being incarcerated since last March in lieu of $200,000 bond and has acquired "a couple of black friends" at Baltimore City Jail. As he imposed the 36-month sentence, U.S. District Judge J. Frederick Motz said he hoped White would come to respect "black people, white people, Jewish people." White pleaded guilty in July to conspiracy to possess two unregistered hand grenades. He also admitted to illegal possession of nine shotguns, five rifles and six handguns seized by federal Bureau of Alcohol, Tobacco and Firearms agents during a raid March 31 on White's house in Harford County. Because of his 1981 synagogue conspiracy conviction, he was charged with illegal possession of weapons as a convicted felon. Two other Klan activists, Leo Joseph Rossiter, 37, and Steven Dale McClellan, 32, both of Baltimore, pleaded guilty in August to conspiracy to possess the same hand grenades that White admitted to having. They are to be sentenced Nov. 3. The grenades were allegedly hidden at various locations in Baltimore for the last two years. There was no public evidence about what the Klan intended to do with them. In July, White pleaded guilty in Baltimore Circuit Court to racial harassment and assault with intent to murder on a black Baltimore garbage collector in a fight involving four men outside a bar in March. White's Klan organization, one of two or three in Maryland, is believed to have fewer than 15 members, according to the Anti-Defamation League of B'nai B'rith, which monitors extremist groups.