An assistant Maryland medical examiner said yesterday he never told Prince George's County police that Maria C. Gertson, whose teen-age daughter is charged with murdering her, died as a result of homicide.

Dr. Dennis Smyth said that when he conducted an autopsy on the body of Mrs. Gertson, 48, he saw no signs that the woman had been murdered.

Lt. Robert Miller, chief of the Prince George's County police homicide division, said on Friday that Smyth told police at the time of the May 25 autopsy that the death appeared to be a homicide. Miller repeated yesterday that "we didn't know about the ruling of natural death until Friday."

"I never told them that," Smyth said yesterday. "There were no bruises on the head at all." Smyth said there appeared to be a lesion on the brain--possible evidence of a natural death.

Smyth said he postponed making a final ruling until the brain could be studied two weeks later.

Police arrested Maria Gertson's daughter, Victoria, 14, on June 1 and charged her with first degree murder. That was at least 13 days before the brain study was ever conducted, according to Smyth.

Police sources said homicide detectives will meet later this week with county prosecutors to decide if charges against Gertson should be dropped. Neither state's attorney Arthur A. Marshall nor Stephen Orenstein, his assistant in charge of new cases, was available for comment yesterday.

Medical examiner Smyth also said he informed police in mid-June that Mrs. Gertson's death appeared to have resulted from a brain abscess caused by a bacteria infection. Smyth said the detective he telephoned with that information told him the victim's daughter already had been charged with murder.

Smyth said he also told the detective that he would await results of more detailed tests before issuing a final report. Those additional brain studies, conducted by Dr. Juan C. Troncoso of Johns Hopkins University Hospital earlier this month, confirmed natural death. Last week Smyth sent police the final report, saying that Gertson's "manner of death was natural."

"There appears to be a lack of communication (with the police department)," Smyth said yesterday. Smyth added, however, that because final autopsy reports often take as long as six weeks, it is not unusual for police to charge a person as a result of their own investigation.

"As a rule, they do not consult me," Smyth said.

Smyth said he made two unsuccessful attempts last week to reach assistant state's attorney Orenstein to inform him of the final autopsy report.

Police allege that on May 21, during an argument in their home at 8402 12th Ave., Langley Park, Victoria Gertson struck Maria Gertson's head against a nightstand. Maria Gertson was taken to Washington Adventist Hospital, where she remained in a coma until her death on May 24.

Lt. Miller said yesterday that the possibility that Mrs. Gertson did not die of natural causes was first raised in a report by Dr. John Rogers, a deputy medical examiner in Montgomery County. According to Victoria Gertson's attorney, Joseph DePaul, that report said a CAT-scan on May 22, two days before Mrs. Gertson died, indicated that she may have suffered a brain concussion or contusion.

The teen-ager went into hiding after her mother's death until police arrested her on June 1. Victoria Gertson was charged with first degree murder. She was held without bond until an Adelphi woman, with whom Victoria Gertson is now living, arranged for her release on $30,000 bond.