A wife of a federal employee has died after a gunman shot her in the neck while she was in her car with her family, according to Drug Enforcement Administration (DEA).

The victim was identified as Tracy Czaczkowski. Her husband has been a DEA employee for 11 years.

Dane County Sheriff David Mahoney earlier called it “a random act.” The gunman, who was later shot by law enforcement, is in police custody.

The shooting happened Sunday afternoon on Interstate 90/94 as the victim, her husband and their two children were driving home to Illinois from the Wisconsin Dells area.

They were passing a Chevrolet Blazer when the Blazer driver rolled down his window and fired three rounds at their car, the Sauk County Sheriff’s Office said.

It was the second round that went into the passenger window and hit the victim’s neck. The mother was hospitalized in critical condition. The sheriff’s office said the man and the children were not injured.

Meanwhile, the gunman — with his two brothers as passengers — kept driving. The Dane County Sheriff’s Office says another car was also struck by gunfire but the driver wasn’t injured.

Witnesses called 911 and officers pursued the gunman’s car, deploying road spikes to stop it. The suspect then got out of the car and walked toward the officers armed with a revolver, the sheriff’s office said. After ignoring commands to stop, the suspect was shot by officers, according to police.

The sheriff’s office says the suspected gunman, a 22-year-old from West Allis, Wisconsin, is also the suspect in a murder at an apartment building in West Allis the morning of the drive-by shooting.

The gunman, whose identity was not released, is being treated at a local hospital and is in the custody of the Dane County Sheriff’s Office.

The gunman’s brothers are being held at the Dane County Jail, the sheriff’s office said.

The shooting remains under investigation. Anyone who saw the shooting is asked to call the Dane County tip line at 608-284-6900.

(By Emily Shapiro ABC News)