When NY1 first revealed that lawyer Richard Luthmann impersonated Staten Island politicians on Facebook, he told us he was only engaging in "dirty tricks."

A special prosecutor disagreed Thursday, announcing a grand jury indicted Luthmann on 17 misdemeanor counts, including identity theft, stalking, and falsifying business records.

Social media dirty trick...or is it a crime? Richard Luthmann is at the center of this question, as he’s indicted after @NY1 reporting that outed him as the man behind several phony Facebook pages last summer. pic.twitter.com/RfqJgKs3wx — Amanda Farinacci (@amandafarinacci) November 29, 2018

"We're pleading not guilty, and it remains to be seen whether or not these allegations rise to the level of just being, let's say, modern day politics, or do they rise to the level of being a crime?" defense attorney Joseph Sorrentino said.

The investigation began after NY1 reported that Luthmann created and oversaw Facebook pages made to look like the actual pages of elected officials and candidates, like Staten Island District Attorney Michael McMahon and Councilwoman Debi Rose.

"I felt threatened," Rose said. "I did at times question my safety."

One of Luthmann's most notable deceptions is a focus of the indictment: a page created in the name of Janine Materna, who mounted a primary challenge against Republican Assemblyman Ron Castorina two years ago.

In a Facebook Messenger exchange revealed by NY1, Castorina wrote, "janine materna filed a committee."

Luthmann replied, "Time for a fake Janine Materna site..."

"Is there a picture of her with Hillary?" Luthmann asked.

"i'm looking for one," Castorina answered.

A doctored image of Clinton standing with Materna later was posted with the statement, "On September 13" — the date of the GOP primary — "we will make HERstory!" It was a message intended to turn off Republican voters.

Another post said, "Black Lives Matter," and showed Materna with Democrat Attorney General Eric Holder. One response was, "Hon you just lost my vote."

The charges come amid rising concern about social media being used to mislead voters. Experts say it is the first criminal case of its kind in the state.

"As we progress forward quite frankly into 2019, 2020, the question will be, Are they going to be still dirty tricks or are they just going to become tricks because more and more people utilize them?" Sorrentino said.

The Materna page did have a disclaimer that said, "This is an UNOFFICIAL FAN PAGE." But the special prosecutor says that was only added after Luthmann realized people were on to him.

Luthmann is due back in court February 13.