TRENTON -- The greatest terrorism threat facing New Jersey is likely already here, according to an annual counter-terrorism report that found domestic attacks across the U.S. were on the rise.

The 2017 "threat assessment" from the state Office of Homeland Security and Preparedness ranks homegrown violent extremists as the single-highest threat to the New Jersey, months after the Garden State saw its first major terror attack since 9/11 with bombings allegedly carried out by an Elizabeth resident.

Chris Rodriguez, the office's director, said that incident shows "the public is really on the front lines" in an era of lone wolf assaults.

The report, which was declassified and released by the office on Tuesday, found homegrown violent extremists -- defined as those inspired by foreign extremist groups but radicalized in the countries where they live -- were the only category presenting a "high" threat level to the state.

That's similar to the office's findings from the previous year, but data shows the number of attacks nationally is on the rise.

A review done by the homeland security office found 22 domestic terror attacks and 17 plots, threats of violence, and instances of weapons stockpiling in 2016. The previous year, the office counted just 16 instances in each category.

New Jersey's homeland security office published its annual ranking of terror threats to the state. Reporter S.P. Sullivan talks with Christopher Rodriguez, the director of that department, about what it means for New Jerseyans. Posted by NJ.com on Tuesday, January 17, 2017

The report details lessons learned from the string of bombings in New York and New Jersey allegedly carried out last year by Elizabeth resident Ahmed Khan Rahimi, who officials describe as a textbook example of a homegrown violent extremist.

Rahimi, who authorities described as a self-radicalized jihadi who espoused the teachings of the deceased Muslim extremist cleric Anwar al-Aulaqi, pleaded not guilty to a host of state and federal charges after he was arrested following a shoot-out with police in September.

In an interview ahead of the report's release, Rodriguez said such suspects are among the most difficult for law enforcement to detect, but added there are "disruption points" in the run-up to their attacks where relatives, community members, and religious figures can intervene.

Increasingly, he said, tips from the public are crucial to stopping would-be terrorists in their tracks.

"It was the bar owner in Linden who saw Rahimi -- or someone matching his description, sleeping in the doorway of his establishment -- that led Linden police to Rahimi's location," he said. "It was two members of the public who saw the backpack at the Elizabeth train station with the pipe bombs in it who reported that to police."

John Cohen, a Rutgers University professor and former official at the federal Department of Homeland Security, told NJ Advance Media the report's findings are "in line with what we're seeing nationally."

"Today the most significant threat facing the U.S. is people who are inspired by extreme ideology, willing to commit mass murder on behalf of that ideology, but unconnected to any specific terrorism organization," he said.

Cohen said there are similarities between the suspect in the New Jersey bombing and those in other high-profile acts of terror across the country, from the targeted killing of police officers in Dallas to the gay nightclub massacre in Orlando.

They are often "ideologically ignorant," meaning they have only a surface-level understanding of the politics or religion they espouse, he said. They may have "behavioral or mental health issues." And they act alone.

The 2017 report rates seven other distinct extremist groups as a "moderate" threat. Those groups range from foreign entities such as al-Qaida and the Islamic State to anarchist, black and white separatist, sovereign citizen and militia extremists here in the United States.

It ranks as a "low" threat a series of other foreign groups, as well as domestic groups with little activity in and around New Jersey, such as animal rights or anti-abortion extremists.

Rodriguez said the report is an analysis of information that is largely in the public domain, and makes a distinction between groups that simply engage in radical politics and those who perform acts of terror.

"For us, the measuring stick is committing violence," Rodriguez said. "Up to that point, an individual -- a white supremacist, a neo-Nazi -- can say whatever they want under the constitution. But it's when it comes to violence is when that raises our attention."

The report also found that while hacking and cybercrime pose a serious threat nationally, there was little evidence that terror groups "possess the cyber capability or intent to damage New Jersey's critical infrastructure."

S.P. Sullivan may be reached at ssullivan@njadvancemedia.com. Follow him on Twitter. Find NJ.com on Facebook.