Vance Boelter allegedly made it to the homes of two other legislators on the night of the attacks, but one was on vacation and the suspect left the other house after police arrived, acting U.S. Attorney Joseph Thompson said Monday.

All of the politicians named in his writing were Democrats, including more than 45 state and federal officials in Minnesota, Thompson said. Elected leaders in Michigan, Ohio and Wisconsin said they, too, were mentioned in his writings.

Investigators say Boelter appeared to spend months preparing for the shootings — the latest in a string of political attacks across the U.S.

In Minnesota, Boelter carried out surveillance missions, took notes on the homes and people he targeted, and disguised 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 surrendered to police Sunday night after they found him in the woods near his home after a massive two-day search. He is accused of fatally shooting former Democratic House Speaker Melissa Hortman and her husband, Mark, in their home early Saturday in the northern Minneapolis suburbs.

Authorities say he also shot and wounded Sen. John Hoffman, a Democrat, and his wife, Yvette, who lived a few miles away.

Federal prosecutors charged Boelter, 57, with murder and stalking, which could result in a death sentence if convicted. He already faces state charges, including murder and attempted murder. At a federal court hearing Monday in St. Paul, Boelter said he could not afford an attorney. A federal public defender was appointed to represent him, and he was being held without bail pending a court appearance next week.

Manny Atwal, his lead attorney, declined to comment, saying the office just got the case.

Notebooks show careful planning

Boelter had many notebooks full of plans, Thompson said. Underscoring what law enforcement officials said was the premeditated nature of the attacks, one notebook contained a list of internet-based people search engines, according to court records.

But authorities have not found any writings that would “clearly identify what motivated him,” Thompson said. He said it was also too soon to speculate on any sort of political ideology.

Democratic Rep. Esther Agbaje, whose district includes parts of Minneapolis, said she stayed with friends and family over the weekend after learning that her name appeared on the list of targets.

In texts, the suspect said he ‘went to war’

Authorities declined to reveal the names of the other two lawmakers whose homes were targeted but escaped harm. Democratic Sen. Ann Rest said she was told the suspect parked near her home early Saturday. She said in a statement that the “quick action” of law enforcement officers saved her life.

Boelter sent a text to a family group chat after the shootings that said: “Dad went to war last night … I don’t wanna say more because I don’t wanna implicate anybody,” according to an FBI affidavit.

His wife got another text that said: “Words are not gonna explain how sorry I am for this situation … there’s gonna be some people coming to the house armed and trigger-happy and I don’t want you guys around,” the affidavit said.

Police later found his wife in a car with her children. Officers found two handguns, about $10,000 in cash and passports for the wife and her children, according to the affidavit.

Just hours after the shootings Saturday, Boelter bought an electric bike and a Buick sedan from someone he met at a bus stop in Minneapolis, the federal affidavit said. Police found the sedan abandoned on a highway Sunday morning.

In the car, officers found a cowboy hat Boelter had been seen wearing in surveillance footage as well as a letter written to the FBI, authorities said. The letter said it was written by “Dr. Vance Luther Boulter” and he was “the shooter at large.”

The car was found in rural Sibley County, where Boelter owned a home.

Coordinated attacks on legislators

The Hoffmans were attacked first at their home in Champlin. Their adult daughter called 911 to say a masked person had come to the door and shot her parents.

Boelter had shown up carrying a flashlight and a 9 mm handgun and wearing a black tactical vest and a “hyper-realistic” silicone mask, Thompson said.

He first knocked and shouted: “This is police.” At one point, the Hoffmans realized he was wearing a mask and Boelter told them “this is a robbery.” After Sen. Hoffman tried to push Boelter out the door, Boelter shot him repeatedly and then shot his wife, the prosecutor said.

A statement released Sunday by Yvette Hoffman said her husband underwent several surgeries after being hit by nine bullets.

After hearing about a lawmaker being shot, officers arrived just in time to see Boelter shoot Mark Hortman through the open door of the home, according to the complaint. They exchanged gunfire with Boelter, who fled into the home before escaping, the complaint said. Melissa Hortman was found dead inside, according to the document. Their dog also was shot and had to be euthanized.

Search for motive continues

Writings recovered from the fake police vehicle included the names of lawmakers and community leaders, along with abortion rights advocates and information about health care facilities, said two law enforcement officials who spoke to The Associated Press on condition of anonymity because they were not authorized to discuss details of the ongoing investigation.

Friends and former colleagues interviewed by the AP describe Boelter as a devout Christian who attended an evangelical church and went to campaign rallies for President Donald Trump.

Boelter also is a former political appointee who served on the same state workforce development board as Hoffman, records show, though it was not clear if they knew each other.