Plymouth District Attorney investigating death of man whose body was found four days after leaving hospital

Authorities said Riviello’s body was found outdoors in Plymouth on Saturday, but did not provide further details.

Beth Stone, spokeswoman for Plymouth District Attorney Timothy J. Cruz, said the office’s Criminal Investigation Division is investigating Riviello’s death, as it does all unattended deaths in the county. The investigation was ongoing Sunday, Stone said.

The state Office of the Chief Medical Examiner will determine Riviello’s cause and manner of death, according to Elaine Driscoll, a spokeswoman for the Executive Office of Public Safety.

Authorities released few additional details about the investigation on Sunday. Riviello lived in the Manomet neighborhood of Plymouth, police said.

When he was last seen, Riviello was walking from the hospital down Sandwich Street toward Jabez Corner, police said in a Facebook message posted during the search. He went missing while the region was experiencing an intense heat wave, with felt temperatures exceeding 100 degrees through Friday.

Riviello’s family offered a $5,000 reward for information leading to his safe return, authorities said during the search. After he was found dead, officials mourned Riviello in a statement Saturday.

“The members of the Plymouth Police and Fire Departments extend their sincere condolences to Mr. Riviello’s family and loved ones,” the statement said.

In response to questions from the Globe, Plymouth Police Capt. Jason Higgins said the city’s police and fire chiefs would meet with prosecutors on Monday to discuss what information officials would release in the case.

Representatives of Beth Israel Deaconess-Plymouth, part of the Beth Israel Lahey Health system, declined to answer questions from the Globe on Sunday.

“We are saddened to learn of Mr. Riviello’s passing and our thoughts are with his family during this difficult time. Due to patient privacy, BID Plymouth does not comment on or share individual patient health information,” hospital spokeswoman Kristina Murray said in an email.

The email also stated that while the hospital could not comment on individual cases, it was its policy to offer patients a ride after they were discharged if needed.

Riviello’s family has asked for privacy.

In an interview before Riviello’s body was found, his son told the Plymouth Independent news site that Riviello and his wife moved to Plymouth from upstate New York about 18 months ago to be closer to family.

His father suffered several mild strokes and his problem-solving skills were “diminished,” son Dan Riviello said, the news site reported. His parents usually go for walks, and on Tuesday his mother visited him in Provincetown, where he works as an assistant town manager, Dan Riviello said.

Dan Riviello told the news site he believes his father went for a walk on Tuesday morning.

Dan Riviello said medical records show his father suffered a broken nose and a bruised head. According to the news site, his father did not have his wallet or phone at the hospital.

In a statement to WCVB-TV, the family mourned the loss of Riviello and thanked everyone who helped search for him, including police.

“We are devastated by the loss of our father. This whole ordeal has been extremely difficult and unbelievable. The only consolation we have had this week has been the hope that our father will come home safely and the incredible support we have received from our family, friends, the media and the Plymouth community,” the family said.

John Hilliard can be reached at [email protected].