A woman whose bulldogs fatally mauled two people, including a 91-year-old man, was sentenced Thursday to spend up to 15 years in prison.

Livingston County Circuit Judge Stanley Latreille ordered Diane Cockrell, 52, to pay more than $30,000 in restitution as well as serve from 43 months to 15 years behind bars.

Cockrell pleaded no contest last month to two felony counts of keeping dangerous animals causing death and a misdemeanor charge of allowing her dogs to stray. A no-contest plea isn't an admission of guilt but is treated as such for sentencing.

Authorities said four of Cockrell's dogs attacked Edward Gierlach, 91, in his driveway and pounced on 56-year-old Cheryl Harper, who was walking or jogging nearby. The attacks happened last September near Cockrell's home in Livingston County's Iosco Township, about 45 miles west of Detroit.

Cockrell had a horse farm on the property, and authorities said the wooden fence surrounding it was not adequate to keep dogs from escaping. Authorities euthanized her 10 dogs.

Defense attorney Daniel Blank said Cockrell "had no idea that her dogs were capable of attacking and killing other human beings."

Blank said Cockrell's "very, very tragic case" should be a lesson to dog owners to make sure their animals are properly secured and controlled. Even a normally gentle pet, he said, is an animal that can act in unanticipated and sometimes dangerous ways, especially in a pack.

Cockrell will report to prison Jan. 2. Blank said the delay is to allow her to receive treatment for health problems.