The man accused of killing a Minnesota lawmaker and wounding another went to the homes of two other lawmakers to carry out more carnage on the night of the shootings, a federal prosecutor said.

But one of the other lawmakers wasn't home, and the suspect left the other house after police arrived, said acting U.S. Attorney Joseph Thompson.

Vance Boelter surrendered to police Sunday after they found him in the woods near his home following a massive manhunt that began early Saturday near Minneapolis.

"Boelter planned his attack carefully" by researching his intended victims and their families and conducting surveillance of their homes and taking notes, Thompson said.

"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. The resulting search, he said, was the largest manhunt in the state's history.

Hennepin County Attorney Mary Moriarty said at a news conference Monday that she plans to file first-degree murder charges against Boelter. The maximum penalty upon conviction of first-degree murder is life imprisonment without parole in Minnesota, which is not a death penalty state.

Authorities initially charged him with second-degree murder and attempted murder — the highest charges that could be filed in a criminal complaint when there is probable cause to believe a crime has been committed.

Boelter is accused of posing as a police officer and 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 state Sen. John Hoffman, also a Democrat, and his wife, Yvette. They were injured at their residence 9 miles away.

"One man's unthinkable actions have altered the state of Minnesota," Democratic Gov. Tim Walz said at a news conference after Boelter's arrest.

The manhunt began when Brooklyn Park officers went to check on Hortman's home and saw her husband gunned down before the shooter fled.

Authorities on Sunday spotted a vehicle Boelter had been using abandoned in rural Sibley County, where he lived, and a police officer reported that he believed he saw Boelter running into the woods. Police called in 20 tactical teams, divvying up the area and searching for him.

During the search, police said they confirmed someone was in the woods and searched for hours, using a helicopter and officers on foot, until they found Boelter. He gave himself up to police, crawling out to officers in the woods before he was handcuffed and taken into custody in a field, authorities said.

Boelter gave up after being surrounded by police on the ground and in the air, said Drew Evans, superintendent of the Minnesota Bureau of Criminal Apprehension.

Jail records show Boelter was booked into the Hennepin County Jail early Monday and included two mug shots of Boelter wearing an orange prison shirt.

Evans said the violence likely would've continued had Brooklyn Park officers not checked on Hortman's home, causing Boelter to flee.

The Hoffmans were attacked first at their home in Champlin early Saturday. A criminal complaint unsealed after Boelter's arrest indicated their adult daughter called 911 to say a masked person had come to the door and shot her parents.

After police in nearby Brooklyn Park learned that a lawmaker had been shot, they sent patrol officers to check on the Hortmans' home.

Brooklyn Park police officers arrived just in time to see Boelter shoot Mark Hortman through the open door of the home and exchanged gunfire with Boelter, who fled into the home before escaping, the complaint said. Melissa Hortman was found dead inside, according to the document.

Authorities said Boelter posed as a police officer, even allegedly altering a vehicle to make it look like a police car.

A Minnesota lawmaker said Hortman's dog had to be euthanized after being shot in the attack.

Authorities didn't give a motive for the shootings as they announced Boelter's arrest.

A list of about 70 names was found in writings recovered from the fake police vehicle at the crime scene, 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 investigation. The writings and list of names included prominent state and federal lawmakers and community leaders, along with abortion rights advocates and information about health care facilities, according to the officials.

A Minnesota official told AP lawmakers who had been outspoken in favor of abortion rights were on the list. 

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

Just hours after the shootings, Boelter texted friends to apologize for his actions, though he didn't say what he had done.

"I'm going to be gone for a while. May be dead shortly, so I just want to let you know I love you guys both and I wish it hadn't gone this way," he wrote in messages viewed by AP.

On Sunday, U.S. Sen. Amy Klobuchar shared a statement from Yvette Hoffman expressing appreciation for the outpouring of public support.

"John is enduring many surgeries right now and is closer every hour to being out of the woods," Yvette Hoffman said in a text that Klobuchar posted on social media. "He took 9 bullet hits. I took 8 and we are both incredibly lucky to be alive. We are gutted and devastated by the loss of Melissa and Mark."

Brightly colored flowers and small American flags were placed Sunday on the gray marbled stone of the Minnesota State Capitol along with a photo of the Hortmans.

Pam Stein came with flowers and knelt by the memorial. An emotional Stein called Hortman an "absolute powerhouse" and "the real unsung hero of Minnesota government."