The hunt for the man suspected of shooting two Minnesota lawmakers and their spouses while impersonating a police officer, killing one legislator and her husband, continued on Sunday more than 24 hours after the killings.

Vance Boelter, 57, now on the FBI’s most wanted list, is believed to have left the Minneapolis region after allegedly gunning down Democratic state representative Melissa Hortman and her husband, Mark, at their home, according to CNN. Boelter is also suspected of shooting Democratic state senator John Hoffman and his wife, Yvette, at their residence, gravely injuring them.

Authorities have disseminated photos of Boelter to border patrol agents in case he tries fleeing to Canada, CNN said.

The Minnesota senator Amy Klobuchar said on Sunday that authorities believe Boelter remains in the midwest. Klobuchar said on NBC’s Meet The Press that “he may be” in Minnesota and that law enforcement has issued an alert in South Dakota.

“We believe he’s somewhere in the vicinity and that they are going to find him,” Klobuchar said. “But right now, everyone is on edge here because we know that this man will kill at a second.”

Klobuchar urged the public to be cautious if they see Boelter, warning they “should not approach him, that they should immediately call the tip lines and report”.

At about 3.30am local time, police responded to a shooting at Hortman’s house to find Boelter leaving the property dressed as a police officer. They said he exchanged shots with them before escaping on foot.

Police said Boelter’s uniform might appear authentic to most people.

Boelter also drove a vehicle that appeared identical to an SUV police squad car, said Mark Bruley, a local police chief. “It was equipped with lights, emergency lights, that looked exactly like a police vehicle, and yes, they were wearing a vest with Taser, other equipment, a badge very similar to mine, that, no question, if they were in this room, you would assume that they are a police officer,” Bruley said.

Tim Walz, the governor of Minnesota, said the murders appear “to be a politically motivated assassination”.

The Federal Bureau of Investigation has offered a $50,000 reward for information leading to Boelter’s apprehension and conviction. He was added to the FBI’s most wanted list on Saturday.

Before the attacks he reportedly contacted two friends by text message, which they read aloud to the Minnesota Star Tribune: “I made some choices, and you guys don’t know anything about this, but 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 added: “I don’t want to say anything more and implicate you in any way because you guys don’t know anything about this. But I love you guys and I’m sorry for all the trouble this has caused.”

Authorities reportedly said that Boelter left a list of potential targets at the shooting scene. Multiple outlets have reported that it included pro-choice lawmakers, as well as reproductive health clinics.

“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.

She also urged the public not to make any assumptions and allow investigators to work. “But again, they’re also checking out, did he have interaction somehow with these without legislators? Is there more to this?”