A landlady suspected of killing at least five people and burying them in the yard of her Victorian boardinghouse was on parole for drugging three elderly people, police say.

Detectives were seeking the manager of the rooming house, Dorothea Montalvo Puente, 59, for investigation of murder, said Homicide Lt. Joe Enloe.Investigators said they believe seven or eight bodies may have been buried in the yard, based on the number of residents who are missing, Enloe said.

The woman apparently had been cashing some of the victims' Social Security checks for several months, he said. The motive in the deaths was believed to be robbery, he said.

Police using picks and shovels resumed digging for bodies Monday in the tree-shaded yard where neighbors earlier reported a hole had been dug, Enloe said.

Puente was interviewed Friday by police after the first body was discovered but was released for lack of evidence.

Puente was convicted in 1982 of grand theft and imprisoned for drugging three elderly people and taking their possessions after meeting them in bars, police said. She served 21/2 years of a five-year sentence before being paroled, officials said.

The boardinghouse is not a nursing home and did not require a license.

The first body was discovered Friday and was followed by the unearthing of two more bodies Saturday and two others Sunday.

After uncovering the fifth body, police arrested John McCauley, 59, on suspicion of being an accessory to the homicides. McCauley, a resident at the boardinghouse, was arrested after he gave conflicting information, Enloe said.

"We do not believe that this could have been done solely by herself," Enloe said. "We know she's had people help her dig the holes."

Police were unable to determine the identities of the victims or how they died because four of the bodies were wrapped in cloth or plastic, investigators said. They were able to determine the sex of only the first body, "wrapped like a mummy" and described as a gray-haired woman.

The bodies, all found in the fetal position, showed no signs of trauma, according to police, who said autopsies would be performed.