The Montgomery County District Attorney's Office said the suspect, 30-year-old Meredith Williams-Earle, was under the influence and had her two-year-old son in her car when she crashed into a van, killing 72-year-old Winston Staats of Conshohocken.
Williams-Earle and the child were not seriously hurt.
Williams-Earle is a teacher at Interboro High School, and her profile on the school district's website shows she is a Latin teacher.
Action News has learned that she lives with her husband and two children in her childhood home in Bryn Mawr. She attended the prestigious Shipley School and then went on to earn two degrees at the University of Pennsylvania.
The crash happened at the intersection of Spring Mill Road and Morris Avenue in the Bryn Mawr section of the township back on the morning of August 6th.
Police say Staats was driving a delivery van and making a turn onto Morris Avenue when his vehicle was struck in the driver's side by Williams-Earle's Toyota Prius.
Investigators say Williams-Earle was speeding and failed to stop for a stop sign.
The impact of the crash flipped the van over, partially ejecting Staats.
Officers on the scene say Williams-Earle had a strong odor of alcohol and said her eyes were glassy and her speech was slurred. A blue plastic cup, which police say also smelled of alcohol, was found in the car.
Also in the car, police say, was Williams-Earle's two-year-old son, who was in a car seat that was improperly installed and was "extremely loose."
Williams-Earle was taken to the hospital where a blood test was taken. The D.A. said her blood alcohol level was .098, above the legal limit, and she had the prescription drug Ativan, a sedative, in her system.
According to a criminal complaint, Williams-Earle allegedly told police that she took the Ativan the night before, but still felt dizzy in the morning. She allegedly told police that a friend told her that alcohol counteracts the Ativan, so she drank some leftover champagne.
Just before the crash, Williams-Earle allegedly told police that her son asked for some crackers. She allegedly told police that she turned around to give her son the crackers and remembered nothing else.
Williams-Earle was charged on Wednesday and was arraigned on Thursday. Bail was set at $100,000 unsecured.
If she is found guilty of homicide by vehicle while driving under the influence, Williams-Earle faces at least three years in prison.
It remains to be seen if she'll be in the classroom when school resumes next Tuesday.
Officials from the Interboro School District have declined to comment on Williams-Earle's arrest.