Minnesota officials on Sunday evening described a multifaceted manhunt for the suspect accused of killing a state lawmaker and her husband over the weekend, saying they believe the gunman is still alive.

Authorities have issued state and federal warrants for Vance Boelter, the 57-year-old man accused of murder and attempted murder as well as seeking to avoid prosecution. More than 100 law enforcement officers are involved in the manhunt, including local, state and federal agencies.

Officials at a press conference Sunday evening suggested the suspect could be on foot or using “various modes of transportation” to evade authorities.

“We have not concluded exactly how he is getting around the area,” said Drew Evans, superintendent of the Bureau of Criminal Apprehension in Minnesota.

Evans said authorities are unaware of the suspect having a particular destination.

Investigators have received more than 400 tips as they conduct their search. The FBI is offering up to $50,000 as a reward for information leading to Boelter’s arrest. 

There is no indication the alleged gunman worked with others in carrying out the shootings, Evans said.

“We have no indication that the individual that is wanted here did anything other than conduct these acts by himself,” he said.

Former Minnesota state Speaker Melissa Hortman (D) and her husband Mark were killed early Saturday morning at their Brooklyn Park home. Authorities say Boelter, who described himself online as a security professional, fatally shot the couple while posing as a police officer.

State Sen. John Hoffman (D) and his wife were also shot multiple times at their homes 8 miles away. The pair have since received surgery to treat their gunshot wounds. 

Sen. Amy Klobuchar (D-Minn.) shared an update from Hoffman’s wife, Yvette, on Sunday afternoon. Each were struck by more than half a dozen bullets and were continuing to recover at the hospital, according to a statement shared to social media.

Minnesota Gov. Tim Walz (D) has described the shootings as “politically motivated.”

Evans on Sunday evening shared more context about material recovered by authorities, including a document that he said was not a “traditional manifesto.” He described it as a “notebook” with a list of lawmakers and other names mixed in with other writing.

An official who had seen the list told The Hill’s sister network NewsNation that it included “prominent pro-choice individuals in Minnesota, including many Democratic lawmakers who have been outspoken about pro-choice policy positions.”

“I don’t want the public to have the impression that there’s this long manifesto that’s providing all this information and details and then associating it with names,” Evans said, while urging the public not to speculate about a motive.

“We often want easy answers for complex problems,” he said.

Evans noted that authorities have so far “not located any prior threats with this individual toward anybody.”

“We are anxiously awaiting news of justice and will not rest until that happens,” said Mayor Ryan Sabas of Champlin, Minn.