Kneblick, a 26-year department veteran, has been second in command since 2001, serving as acting chief during any of Mendoza's absences. She directs the Executive Services Bureau, one of the department's six bureaus that includes training, internal affairs and staff services.
In 2005, she led the department's response when thousands of evacuees arrived in the city after Hurricanes Katrina and Rita.
She became Fort Worth's first female deputy police chief in late 1995, 14 years after joining the department as a patrol officer on the midnight shift.
City Manager Dale Fisseler said Kneblick has done "an outstanding job."
The city is conducting a nationwide search for a police chief.
