LEWISTON – A retired nursing teacher whose body was found by police in her home is believed to have died six weeks ago.

Marie Sturtevant, 65, who was described by neighbors as reclusive, had a history of heart problems. Her doctor signed the death certificate. The cause of death was not disclosed.

Police forced their way into Sturtevant’s home in a quiet neighborhood Tuesday night in response to reports that she had not been seen.

“I’ve been noticing that her mail was accumulating,” said Mike Nadeau, the letter carrier who would deliver Sturtevant’s mail through a slot in the door. “I knew something was wrong.”

A neighbor, Tom Fredericks, said he had not seen Sturtevant in recent weeks, but that did not seem unusual because she rarely ventured out and did not socialize.

“The last time I saw her was the Thursday after Christmas when she was carrying some trash bags out of her house,” Fredericks said. “We barely saw her.”

Fredericks said Sturtevant cared for the flowers in her yard, but her lawn was sometimes left unmowed and at one point the grass grew 2 feet tall.

“Nobody showed up to mow it, so I went over and did it myself,” Fredericks said. His neighborly deed drew no reaction, and one day Fredericks knocked on Sturtevant’s door to ask whether he should keep mowing it. She agreed and began paying him $20 for the task.

“I mowed her lawn for three years,” Fredericks said. “She’d bring me out a cup of coffee.”

Neighbors seldom had contact with Sturtevant, saying she always kept her doors locked and used deadbolts to secure them.

“I’ve been delivering her mail for more than 20 years,” Nadeau said. “And I talked to her maybe six times.”

A graduate of Boston College who went on to earn a master’s degree in nursing from Catholic University in Washington, Sturtevant was an Army nurse who attained the rank of captain. She later served for many years as a nursing instructor at St. Joseph’s College in Standish.

Her obituary said she had a sister in Lisbon and an uncle in Lewiston, but many other relatives live out of state.