MINNEAPOLIS (Reuters) -A massive manhunt entered a second day on Sunday in Minnesota for the gunman who killed a Democratic state lawmaker while posing as a police officer, a crime that Governor Tim Walz characterized as a "politically motivated assassination."

The suspect, whom police identified as Vance Luther Boelter, 57, fled on foot when officers confronted him at the Brooklyn Park home of state Representative Melissa Hortman, the top Democrat in the Minnesota House, and her husband, Mark, who were both killed.

The gunman earlier had shot and wounded another Democratic lawmaker, state Senator John Hoffman, and his wife Yvette at their home a few miles away, authorities said.

Minnesota U.S. Senator Amy Klobuchar, a Democrat, said on Sunday morning that authorities believe the suspect is still in the Midwest, adding that an alert had been put out in neighboring South Dakota.

"Clearly, this is politically motivated," she said on NBC's "Meet the Press with Kristen Welker."

The suspect left behind a vehicle outside Hortman's house in suburban Minneapolis that resembled a police SUV, including flashing lights, and contained a "manifesto" and a target list of other politicians and institutions, officials said.

Authorities had not publicly identified a specific motive as of Saturday evening.

Boelter has links to evangelical ministries and claimed to be a security expert with experience in the Gaza Strip and Africa, according to online postings and public records reviewed by Reuters.

"There clearly was some through line with abortion, because of the groups that were on the list and other things that I've heard were in this manifesto. So that was one of his motivations," Klobuchar said.

ABC News, citing law enforcement officials, reported the list of targets featured dozens of Minnesota Democrats, including Walz, who was also the Democratic vice presidential candidate last year.

The killing was the latest in a series of high-profile episodes of U.S. political violence, including the attack on former Democratic U.S. House Speaker Nancy Pelosi's husband in 2022, the attempted assassination of Donald Trump during last year's presidential campaign, and an arson attack at Pennsylvania Governor Josh Shapiro's house in April.

GUNMAN POSED AS OFFICER

Damon Voight, who lives down the road from Boelter's house in a rural area of Green Isle, Minnesota, said his wife was afraid with the suspect on the loose.

"My wife is freaked out," Voight said. "She's like, 'We've got guns in the house, right?'"

Outside the state capitol in St. Paul, a small memorial had taken shape, with flowers, American flags and handwritten messages on yellow post-it notes.

"Justice for Melissa," read one note, with a drawing of a heart on it.

Klobuchar said she had seen both Hortman and Hoffman at a political dinner on Friday, just hours before they were shot.

"We started out together in politics, moms with young kids, and somehow she was able to balance getting to know every door, knock on every house in her district, while raising two children - Girl Scout leader, she taught Sunday school," the U.S. senator said of Hortman, 55.

Klobuchar said both Hoffmans were "hanging in there" after undergoing surgery for multiple gunshot wounds.

The attacks started around 2 a.m. (0700 GMT) on Saturday, when authorities said the gunman shot the Hoffmans in their home in Champlin before driving several miles to Hortman's home in Brooklyn Park.

The FBI released photos of the suspect wearing a rubber mask and a police-like uniform.

David Carlson, 59, told Reuters he has shared a house in Minneapolis with Boelter for more than a year and last saw him on Friday night. He said he received a disturbing text from Boelter at about 6 a.m. on Saturday.

"He said that he might be dead soon," said Carlson, who called police.

Trump has faced criticism from some opponents for using inflammatory rhetoric at times when talking about his political rivals. On Saturday, he said in a statement: "Such horrific violence will not be tolerated in the United States of America."

In one of his first moves in office earlier this year, Trump pardoned nearly everyone criminally charged with participating in the January 6, 2021, Capitol attack.

(Reporting by Tom Polansek and Nathan Layne; Additional reporting by Michelle Nichols, Leah Douglas, Michael Martina and Katharine Jackson; Writing by Joseph Ax, editing by Michelle Nichols and Bill Berkrot)

By Tom Polansek and Nathan Layne