Almost a year after the mass shooting at Sandy Hook Elementary in Newtown, Conn., local prosecutors said they are about to release the long-awaited report on their investigation – but the public will have to keep waiting for the full police report on the massacre.

The report on the Dec. 14, 2012, shooting, in which 20-year-old Adam Lanza took the lives of 20 first graders, six school staffers and his mother before turning the gun on himself, was supposed to be released in June, then was pushed back to the fall.

The Office of the State’s Attorney for Danbury now says it will publish the summary report Monday afternoon on the state’s Division of Criminal Justice website, www.ct.gov/csao.

Mark Dupuis, a spokesman for Danbury State’s Attorney Stephen Sedensky III, declined to say whether the report has been shared with the families of those who died in the shooting, but he said his office is aware of families' concerns and has taken steps to address those concerns.

Gov. Dannel Malloy told NBC Connecticut that he agrees that the information should be made public and is glad the information will be released.

Michelle McLoughlin / Reuters file Demolition work nears completion at Sandy Hook Elementary School in Newtown, Conn., on Nov. 13. A gunman killed 20 children and six adults at the school before taking his own life last December.

Last month, Malloy called upon Sedensky to release the final report.

"I'm frustrated by the amount of time that it's taken and I think the longer it takes, the more things come out as opposed to being in an official report," Malloy said. "And I think the people of Newtown and families of those injured deserve it."

Malloy added that he has not been briefed on the report.

The summary report to be released Monday will not include the full state police report on the shooting, which is expected to run thousands of pages. No date has yet been set for the release of the full police report, and some evidence from the state's investigation will never be made available to the public.

A state law passed after the massacre exempts certain records of a homicide, including photos and film, from freedom-of-information requests from the press and the public if the records are believed to invade the privacy of survivors.

In advance of the summary report being issued, the interim superintendent of schools in Newtown has reached out to parents and sent a letter to ensure they’re prepared.

"We all understand that for the children who were directly affected by this tragedy the release of the report and the upcoming anniversary can carry a very personal meaning," the letter read.

Reuters and AP contributed to this report.

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