Ronald Q. Ellis was indicted yesterday on six counts of murder in the shooting deaths of his wife, two daughters and three other persons in the Ellises' Camp Springs home May 2.

The 34-year-old Ellis, a pressman for a Silver Spring printing firm, allegedly fled from his home at 6700 Coolridge Rd. after the slayings. He surrendered to the FBI in Washington after eight days as a fugitive.

Hours after the slaying police charged Ellis with the handgun murder of his wife, Ingrid, a D.C. police sergeant, and the shotgun slayings of the five other victims and mounting indications that he and his wife were having serious marital problems.

The county grand jury yesterday also indicted Ellis on two counts of using a handgun to commit a crime of violence.

The indictment in the mass slayings means that Ellis, if convicted, could face the death penalty, which prosecutors may seek in cases of multiple homicide.

Prince George's State's Attorney Arthur A. Marshall said the Ellis trial may be months away because he believes that Ellis' attorney, R. Kenneth Mundy, may seek to have Ellis examined by psychiatrists with a view to using a defense of temporary insanity.

Marshall said yesterday he personally will prosecute the Ellis case. It will be the third major case in which he and Mundy, a prominent D.C. lawyer, have faced each other in a murder trial.