The family of an Illinois Uber driver who was stabbed to death filed a wrongful death lawsuit on Monday against Wal-Mart Stores Inc for failing to stop the teen suspect in the incident from stealing a machete and knife from one of its stores.

The lawsuit was filed in the Cook County Circuit Court by the family of Grant Nelson, 34. Nelson was killed early on May 30 after picking up 16-year-old Eliza Wasni outside a Wal-Mart in Skokie, Illinois, around 16 miles (26 km) north of Chicago.

Wasni, a high school student, was arrested shortly after the attack and charged in June with first-degree murder. She is being held without bail, the Chicago Tribune reported.

The family is seeking unspecified financial damages.

In addition to Wal-Mart, the lawsuit names Allied Universal and Monterrey Security Consultants as defendants, according to court documents. Both companies provided security services to the store.

Wal-Mart said in a statement that it would respond "appropriately" with the court, "but we can say that we believe our associates acted properly, including alerting third-party security to a possible shoplifting incident."

Allied Universal and Monterrey Security Consultants did not immediately respond to requests for comment.

Privately held Uber Technologies Inc [UBER.UL] has grown from startup to a global ride service valued at $68 billion in less than a decade but has faced criticisms on issues ranging from corporate culture to driver payment.

An attorney for Nelson's family, Robert Bingle, said in a statement that it was "very obvious that this young girl with a machete in one hand and a knife in the other hand, with no receipt, was not going to do anything good."

He said the tragedy could have been avoided "if Wal‐Mart and its agents had simply followed their own procedures." He said Wasni was not stopped, questioned or asked to show a receipt at the store's exit door.

After shoplifting the machete and knife, Wasni called an Uber and Nelson drove to pick her up, according to court documents.

Two minutes into the ride, she attacked Nelson from behind, Cook County Assistant State's Attorney Michelle Cunningham said.

Nelson was able to exit the car and made his way to a nearby condominium building where he yelled for help, the Chicago Tribune reported.

Wasni fled in Nelson's car before crashing and fleeing on foot. She was then apprehended by police. The motive for the killing remains unknown.