A Wisconsin man gunned down an off-duty corrections officer in a road rage incident that unfolded as she was teaching her teenage son how to drive, authorities said.

Matthew Lee Wilks, 35, of Whitefish Bay, was charged with first-degree intentional homicide and possession of a firearm by a felon, according to Milwaukee County Sheriff's Department records.

Matthew Wilks. Milwaukee County Sheriff's Office

The victim, Tracey Smith, was a Department of Corrections sergeant, officials said.

Smith was in her car teaching her 17-year-old son how to drive when their vehicle was struck by Wilks' gold van a little after 5 p.m. on Aug. 30 on N. 39th St., Milwaukee police said.

The minor fender-bender happened when Wilks made a turn out of the wrong lane, the victim's son told investigators. Both drivers stopped, and an "upset" Smith got out of the car and began "yelling at the driver of the van," according to the criminal complaint filed by Milwaukee County prosecutors.

"B----, I"ll kill you," Wilks allegedly said before firing one shot into Smith's chest, authorities said.

"He shot me," Smith said before stumbling and falling to the ground, according to prosecutors.

Wilks, who has a previous conviction for cocaine possession, was being held in lieu of $110,000 bail, according to jail records.

"That was a real weak man move to sit there and shoot a lady in front of her son,” Smith's sister, Sherri Luckett, told NBC affiliate WTMJ.

Wilks fled the scene but nearby security cameras captured his license plate and he was arrested on Monday, officials said.

“What was she supposed to do?” Luckett said of her slain sister. “Sit there in the car hoping he fled the scene?”

Wilks' defense lawyer could not be immediately reached for comment on Friday.

Smith "was well respected and she was an especially important leader and bright light for her family and friends," Alderman Khalif Rainey said in a statement.