A woman whose 13-month-old son was struck and killed during a high-speed police chase in Chicago is suing the city, saying officers ignored orders to stop the chase 20 minutes earlier.

Lawyers for Shatrelle McComb discussed the lawsuit Thursday. McComb was waiting at a bus stop with her son when a driver fleeing police struck her son's stroller July 11.

Authorities say police were pursuing the suspect, Antoine Watkins, after a fatal shooting when he lost control of his vehicle, which went onto a sidewalk and struck the stroller.

Attorney Antonio Romanucci says he has "direct evidence" officers were told to end the pursuit. He wouldn't elaborate, but says he's asked that audio recordings and dash-cam video be preserved.

A police spokesman says the department can't comment on pending litigation.