A 24 year old Harrisburg woman is facing felony charges after police say she was using Snapchat when she struck and killed a 16 year old in Lancaster County. Investigators say Mikayla Mustard hit Curtis Groff while he was weed-whacking along West Sun Hill Road last May, then left the scene. She later returned, telling police she thought she hit a deer. Data from her phone showed Snapchats sent before and after the crash, including one about blood on her car. She’s due in court today.