Connecticut leaders said they were horrified – but not surprised – by this weekend’s deadly ambush on two Minnesota lawmakers and their families.

In Hartford, State Capitol Police have increased security, but stress there are no “credible” threats against lawmakers locally.

For Norwalk’s Bob Duff, the top Democrat in the state Senate, the shootings hit home.

“I’ve had threats where people called my office, they called my home,” Duff said. “A person said he’d threaten to take the back of my head off because of a bill I'd proposed.”

Duff was also friends with one of the victims, former Minnesota House Speaker Melissa Hortman.

“It’s a punch to the gut,” he said. “It’s a reminder how we need to be careful, and none of us are immune to this.”

The man accused of killing Hortman and wounding a Minnesota state senator went to the homes of two other legislators on the night of the shootings, intending to inflict more carnage against those on his hit list, a federal prosecutor said Monday.

But one of the other state lawmakers was on vacation, and the suspect left the other house after police arrived early Saturday, acting U.S. Attorney Joseph Thompson said at a press conference.

The suspect, Vance Boelter, meticulously planned the attacks, carrying out surveillance missions, taking notes on the homes and people he targeted and disguising himself as a police officer just before the shootings, Thompson said.

“It is no exaggeration to say that his crimes are the stuff of nightmares,” he said.

Boelter had many notebooks full of plans that appeared to be months in the making, but authorities have not found any writings that would “clearly identify what motivated him,” Thompson said.

Though the targets were Democrats and elected officials, Thompson said it was too soon to speculate on any sort of political ideology.

“This was a targeted attack against individuals who answered the call to public service,” said Alvin Winston, the special agent in charge of the FBI’s Minneapolis field office.

His writings included the names of 45 state and federal elected officials in Minnesota, Thompson said.

In Connecticut, State Capitol Police protect the complex and investigate threats against lawmakers and staff. Gov. Ned Lamont travels with a small security detail.

“While we don’t have any credible information suggesting any threat to officials in Connecticut, we understand there’s concern,” said Sgt. Michael Bermudez, with State Capitol Police. “We’re always vigilant and just assessing the information that we’re getting from our partners statewide and from our federal partners.”

The Capitol complex has 300 surveillance cameras. While officials declined to detail their exact security protocols, previous Gov. Dannel Malloy’s former criminal justice advisor said they are extensive.

“The Connecticut State Capitol Police have a database where there are individuals about whom they’re very concerned,” said Mike Lawlor, who now teaches at the University of New Haven. “There are people who have been banned from entering the state Capitol for a variety of reasons.”

There are limits, though.

Threats against federal officials can be investigated through the U.S. Secret Service’s National Threat Assessment Center.

But state and local officials are increasingly at risk – especially with the rise of social media and “dark web” sites. Policing them is a massive investment, according to former FBI agent Ken Gray, who also teaches at UNH.

“Especially at a state level, it’s not like they have a huge budget to afford something equivalent to Secret Service,” he said.

Connecticut investigators have resources though.

“We do have lots of experience, for example, with the Red Flag Law, which is the same assessment,” Lawlor said. “You try and figure out, are there other indicators? For example, any reason to believe this person has access to firearms? Do they have a criminal record?”

The "Red Flag Law" allows police to temporarily seize guns from someone deemed a threat.

Duff said this is the most dangerous environment he’s seen in two decades at the state Capitol.

He feels safe there, but what about everywhere else?

“That was done at their homes. It wasn’t done at the state Capitol, so that's why we have to be extra vigilant. We have to be careful,” he said. “We can't all have 24-7 security like the president does. And so that’s why we have to be vigilant ourselves.”