MEDFORD — Police found the body of “a beloved member of the Medford community” in a recycling bin beneath the back porch of her home near Tufts University on Monday, hours after her son had reported her missing, authorities said.

Barbara Novaes, 61, was last seen alive Sunday afternoon, and Middlesex District Attorney Marian Ryan said in a news conference Monday night at Medford police headquarters that her death is considered suspicious.

“Based on the circumstances and the location of the body, this is being investigated as a suspicious death,” Ryan said. “It is a very active and ongoing investigation.”

Novaes, whom neighbors described as a friendly longtime member of the community, had lived in a duplex at 21 Emery St. with her college-aged son, Ryan said. Her son told police he had last seen her around 4:30 p.m. Sunday, and that he believed she was going to get a manicure, Ryan said.

When her son awoke the next morning, he found the front door of the home ajar and located his mother’s cellphone, keys, and wallet inside the house, Ryan said, and he saw that her car was parked outside. About 6:30 a.m. he called police, who found his mother’s body around two hours later “inside a recycling container in an enclosed area under the porch,” Ryan said.

Novaes’s body had no obvious signs of trauma, Ryan said. She had been in contact with Medford police in the past for “a variety of reasons.”

Medford’s mayor, Breanna Lungo-Koehn, said Novaes “was a beloved member of the Medford community and a very active parishioner at Grace Church” who touched many lives.

Ryan did not indicate whether there were signs of forced entry at the home. She advised residents of the area to exercise caution as police work to uncover the circumstances of Novaes’s death.

“People should obviously exercise the same caution we would urge them to exercise all the time: keeping your doors locked [and] being cautious of who is around the house,” Ryan said.

Emery Street was expected to be closed through late Monday night, and Ryan said there will be an ongoing police presence in the neighborhood.

The tree-lined street, located only a block from Tufts, is normally quiet, residents said. But on Monday, it was abuzz with police cars and helicopters hovering overhead as authorities worked to clear the scene.

A crowd of anxious neighbors gathered to watch from the other side of the street as police carried a cloth-covered stretcher from behind the house and loaded it into a van from the state’s Office of the Chief Medical Examiner. A few gasped. Others shook their heads.

Down the street, one woman, who asked that her name not be published, paced back and forth. She said she could not bear to watch.

“I knew her,” the woman said. “She was my friend. She was the sweetest woman. I was walking by her house on Saturday and she was out weeding and she waved to me. How can she be gone?”

Novaes, the woman said, had lived in the neighborhood for as long as she could remember. She was friendly with everyone on the street, she said, and always stopped to say hello and strike up conversation.

Novaes always knew what was going on in the neighborhood, the woman said. If she was not the person police were searching for on Monday, the woman said, she would’ve been the first out in the street seeking information.

“She would have been wanting to know what was going on and then letting everyone know. That’s who she was. I want to go over there and ask [Novaes] what’s happening ... but I can’t. She’s gone.”

Andrew Brinker can be reached at andrew.brinker@globe.com. Follow him on Twitter at @andrewnbrinker.

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