The chairman of the Georgia GOP and the leader of a conservative voting organization criticized one of the state’s top law enforcement officials Friday after he concluded there wasn’t enough evidence to warrant an investigation into their claims of election fraud.

The two were responding to a report Thursday in The Atlanta Journal-Constitution on a letter from Georgia Bureau of Investigation Director Vic Reynolds that found a probe of cellphone GPS signals to vet their allegations of ballot harvesting was “not justified.”

Georgia GOP Chair David Shafer wrote to Reynolds on Friday claiming other unsubstantiated examples of “suspicious” activity involving ballot drop boxes.

“I am not going to use this letter to recount every detail of our discussions over the last six months,” he wrote in a letter obtained by the AJC, “but suffice to say, I believe the information provided or offered you cries out for investigation.”

And attorneys for True the Vote, a Texas-based group that last year unsuccessfully challenged the eligibility of 360,000 Georgia voters, threatened to take legal action.

James Bopp, the group’s attorney and a former vice chair of the Republican National Committee, wrote that the GBI’s letter appears to “minimize” its claims of election fraud.

A GBI spokeswoman declined to comment.

The allegation of ballot collections is only one of a wave of unverified claims that Republican Donald Trump lost the presidential vote in Georgia because of illegal behavior rather than receiving fewer votes than Democrat Joe Biden.

Three ballot counts in Georgia showed that Biden defeated Trump by about 12,000 votes, and bipartisan election officials have said there is no evidence of irregularities that would put the outcome in doubt.

State election officials have conducted multiple investigations into allegations of fraud, including audits and recounts, but none has found organized efforts to change the outcome of the presidential election.

In a Sept. 30 letter, Reynolds wrote that GPS signals alone, without any witnesses or perpetrators, fall short of meriting a fresh law enforcement inquiry. He also wrote that Shafer and his allies had failed to produce a “source” that they had alleged could validate their claims.

“Based on what has been provided and what has not been provided, an investigation is not justified,” Reynolds wrote in the letter, which was first reported by the AJC on Thursday.

In Shafer’s response, he provided no new information on the “source” and said he learned of Reynolds’ letter through the AJC.

The state GOP chair’s public call for the GBI to investigate unfounded fraud claims is only one part of his effort to pressure officials to revisit the 2020 election.

Shafer had also told state party officials that he presented similar claims of ballot fraud directly to Gov. Brian Kemp. That brought a sharp backlash from some of Kemp’s supporters, who pointed out the GBI’s legal reasoning for ruling out an investigation.

Writing in the Peach Pundit blog, former state Rep. Scot Turner said Shafer owed Kemp an apology for a move he said was “likely designed to sow seeds of discontent with the governor’s leadership among party officials.”

Shafer declined to comment on private discussions with the governor and members of the party’s leadership.

Democrats and some legal experts, meanwhile, expressed horror about True the Vote’s approach. The group said on its website that it purchased GPS data to map travel patterns of 1.2 trillion mobile signals and then mapped them to find whether they had come close to ballot drop boxes.

Anthony Michael Kreis, a constitutional law professor at Georgia State University, said he finds it “incredibly disturbing” that the groups are demanding a criminal investigation into Georgians doing everyday tasks.

“Not only is the Georgia GOP engaged in this third-rate armchair detective work,” the professor said, “they’re essentially spying on Georgians who are going about their business.”