Search for suspect Vance Boelter enters 2nd day after attacks on Minnesota lawmakers

State Rep. Melissa Hortman and her husband, Mark, were killed in their home.

A massive search continued Sunday for a man suspected in the fatal shooting of Minnesota state Rep. Melissa Hortman and her husband, and a separate shooting attack on another state lawmakers and his spouse, authorities said.

The manhunt for 57-year-old Vance Boelter stretched into its second day following Saturday's twin attacks in Champlin and Brooklyn Park, Minnesota, and the discovery in the suspect's vehicle of an alleged target list of dozens of Minnesota Democrats, including Gov. Tim Walz, U.S. Rep. Ilhan Omar, U.S. Sen. Tina Smith and state Attorney General Keith Ellison, according to law enforcement sources.

The FBI is offering a $50,000 reward for information leading to Boelter's arrest.

"Right now we are asking the public if you do locate him, if you see him, to call 911. Do not approach him. You should consider him armed and dangerous," Superintendent Drew Evans of the Minnesota Bureau of Criminal Apprehension said at a Saturday-evening news conference.

The suspect’s wife was detained for questioning after a traffic stop near Onamia late on Saturday morning, multiple law enforcement sources told Minnesota ABC News affiliate KSTP. She was released without being arrested, according to KTSP, which reports it's unknown why her vehicle was stopped.

Boelter is suspected of gaining entry to the lawmakers' homes by disguising himself as a police officer, even arriving at the victims' home in a vehicle that looked like a police cruiser equipped with flashing emergency lights, officials said.

The shootings unfolded around 2 a.m. Saturday, when Minnesota State Sen. John Hoffman and his wife, Yvette, were both shot multiple times at their home in Champlin, Minnesota, authorities said. John and Yvette Hoffman were both in stable condition after undergoing surgery, KSTP reported.

Soon after the shooting at the Hoffmans' home, state Rep. Hortman and her husband, Mark, were shot and killed at their home in Brooklyn Park, according to authorities.

Police believe the suspect opened fire on the victims while wearing a latex mask, sources said.

Following the shooting at Hoffman's residence, officers were sent to Hortman's home to check on her well-being, officials said. As officers arrived at the residence, they encountered the gunman at around 3:35 a.m. The suspect and the officers exchanged gunfire before the suspect escaped, flee on foot and leaving behind his fake police car, where investigators found his target list, authorities said.

Boelter – a husband and father, according to an online biography – has touted an extensive background in security and military training, according to an ABC News review of his online presence and professional history.

Boelter helped lead the private security firm Praetorian Guard Security Services, which is based in the Twin Cities area, according to the company website.

ABC News' Josh Margolin, David Brennan, Emily Shapiro and Jack Moore contributed to this report.

This is a developing story. Please check back for updates.