Police line do not cross
File photo: US police tape Reuters

A 22-year-old woman is expected to face murder charges after her grandmother was shot dead over the weekend, state police in Macon County, Alabama.

Stephanie Pierson was arrested on Saturday when officers responded to a call outside her grandmother's home and found 58-year-old Ruth Pearl Pierson dead from a single gunshot, reported WSFA.

The family were on their way to the funeral of the mother of Stephanie Pierson's boyfriend when the incident took place, police allege.

Macon County Sheriff said that it was an "unfortunate tragedy" for an incident like this to occur while the family "was on their way to a funeral."

Stephanie Pierson is currently in jail and expected to be charged with murder on Monday, (8 May).

Sheriff Andre Bruson told al.com that it was a "tragedy" and added that the boyfriend had allegedly witnessed the whole altercation. "Then he had to go on to his mother's funeral thinking about that. This was a no-win situation for everybody." Bruson told the site.