[caption id="attachment_260796" align="alignnone" width="480"]Olivia Mora.
Credit: Boston police[/caption] The alleged drunk driver who was arrested for striking and killing 7-year-old Dorchester girl Brianna Rosales is claiming the accident was caused by "bad tires." [related tag = Boston] Olivia Mora, 36, was charged with motor vehicle homicide and driving under the influence after Tuesday’s crash, Boston police said. In addition to having "bad tires," her lawyer claims Mora has "medical issues." Mora's speeding SUV hit a parked vehicle and a fire hydrant before striking Brianna Rosales and her mother, Glendalee Alvarado as they walked home from school on Tuesday, WCVB reports. Police say Mora smelled of alcohol, and then failed a series of field sobriety tests. Mora was arraigned on charges of motor vehicle homicide while operating under the influence, operating under the influence causing serious bodily injury, and operating a motor vehicle with an expired registration. Rosales was taken to Boston Medical Center where she later died. Her mother was also taken to Boston Medical Center for injuries that were not considered life-threatening. Mora is due back in court on Jan. 3. She faces at least a year in jail if convicted of motor vehicle homicide. Follow the Boston Metro on Twitter @MetroBOS. Reported by metronews 3 days ago.