Even as authorities struggle to gather real clues in Friday's horrific attack, they're warning that those promoting misinformation about the case are subject to prosecution.

"Misinformation is being posted on social media sites," Connecticut State Police Lt. J. Paul Vance said at a news conference Sunday. "These issues are crimes. They will be investigated, statewide and federally, and prosecution will take place when people perpetrating this information are identified."

In some cases, Vance said, people are posing as the dead gunman, Adam Lanza. Some are assuming other identities associated with the shooting — and some of the information has been threatening.

One such threat caused the evacuation of a church in Newtown during Sunday Mass. Archdiocese spokesman Brian Wallace says a threatening phone call caused officials to evacuate St. Rose of Lima Catholic Church, where many residents have gathered to seek solace from the tragedy.

The Newtown school shooting has been a story particularly vulnerable to false information, starting with the misidentificationof the shooter by law enforcement and media on Friday. Since then, officials have been careful with the information they do release, warning that it may be weeks before many questions are answered.

Meanwhile, Tom Carson, a spokesman for Connecticut U.S. Attorney David Fein, is underlining the penalty for harassment:

"Anyone who harasses or threatens the victims, the victims' families or witnesses of these horrific crimes or who in any manner interferes with the ongoing state or federal investigations will be referred for state and or federal prosecution to the fullest extent permitted by law. Harassment not only includes in-person contact, but also contact via the internet, social media and telephone."Copyright 2016 NPR. To see more, visit http://www.npr.org/.