Tracy Czaczkowski and her family were driving home after a quick getaway, a trip to Wisconsin Dells, a popular water park north of Madison on May 1. But on the freeway home to Buffalo Grove, Illinois, Tracy was shot dead in a seemingly random attack, right in front of her two children sitting in the back seat.

"The male was passing a Chevrolet Blazer when the operator of the Blazer rolled down his window and fired three rounds into the vehicle," said Sauk County Sheriff Chip Meister.

Tracy was struck once in the throat. Paramedics rushed her to a Madison, Wisconsin hospital, where she died.

An eyewitness who saw the shooting told Crime Watch Daily Milwaukee affiliate WITI the suspect even aimed the gun at her. The woman says she called 911, and deputies chased the suspect down the interstate.

"Our deputies deployed spike strips to deflate the tires of the Blazer and bring that vehicle to a safe stop," said Dane County Sheriff Dave Mahoney.

A suspect got out of the vehicle and walked toward deputies with a gun in his hand. Cops shot the suspect, wounding him.

Police identified the shooter as Zachary Hays. His wounds were not life-threatening. His brother Jeremy, who was in the SUV with him, was also arrested.

Police say hours before the random freeway shooting that killed Tracy Czaczkowski, Zachary was on the run after he allegedly shot and killed Gabriel Sanchez at an apartment in West Allis, Wisconsin.

According to the charging documents, Jeremy Hays told investigators Zachary had smoked weed four days before the shooting and "... Had been acting extremely paranoid ever since."

Jeremy said "Zachary had the .45-caliber pistol in his lap and was pointing it at cars as they drove by." He also said his brother was "... Particularly paranoid about cars with tinted windows."

When Tracy's black BMW came from behind, Jeremy says his brother began "freaking out" about the tinted windows and fired three times.

Police led the funeral procession for Tracy. Her husband is in law enforcement, working for the Drug Enforcement Administration. Investigators don't believe his working for the DEA had anything to do with the shooting.

Zachary Hays remains hospitalized. He hasn't yet entered a plea on a first-degree murder charge. His brother Jeremy is expected to enter a plea next week on a charge of being a felon in possession of a firearm.