A 64-year-old woman found dead in her Mechanicville, New York, apartment is suspected of killing her daughter and four grandchildren, police said Thursday.

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The bodies of Amy Steadman and her daughter, Sarah Myers, 44, were discovered Tuesday evening after a neighbor requested a welfare check, saying that they had not seen Steadman for some time and were concerned, Mechanicville police chief William Rabbitt said at a news conference.

After officers were unable to make contact with Steadman, building management let them into the apartment, he said.

“Upon entering the residence, officers located six deceased individuals,” Rabbitt said.

Myers’ four children — Harper Harmon, 13; Hudson Harmon, 11; and Gavin and Gracelynn Harmon, both 10 — were also found in the apartment.

Rabbitt said the unit belonged to Steadman and that Myers and her children lived in a separate apartment in the building.

The chief said that he believes the family had been dead for “an extended period of time” and that officers could not immediately make identification because of the conditions of the bodies. They were identified after autopsies were conducted on Wednesday, he told reporters.

One of the children is believed to have suffered fatal sharp-force injuries, Rabbitt said. Investigators also “recovered evidence inside the apartment” that indicates intentional poisoning, including “numerous prescription and over-the-counter medications,” he said.

The causes and manners of death for all six people are pending further testing.

A handwritten note found in the apartment “strongly suggests that Amy Steadman was involved in the deaths,” the chief said. He declined to discuss the note’s contents and said there was no evidence to indicate that an outside individual was involved in the deaths.

“However, final determination regarding responsibility will be made only after all investigative findings, toxicology results, and medical examiner reviews have been completed,” the chief said.

The children’s father lives in Utah. The children were homeschooled and were not enrolled in public school, Rabbitt said.