The incident occurred shortly before 6:30 p.m. after 38-year-old Harry Bouchard got into an argument with his wife, 40.
The couple had been married for 14 years, but had been separated since April and was arguing about the custody of their child, Aguinaga said.
The wife told police she hung up on Bouchard, got in her car and started driving. But then she saw Bouchard following right behind her, allegedly attempting to ram her car or force her off the road.
The woman called her brother and told him to meet her in the parking lot of the Walgreens pharmacy on Deer Valley Road. She then called police.
The brother got to the parking lot first and a fight broke out between the woman's brother, 48, and Bouchard, during which Bouchard allegedly bit off the brother's right eyebrow.
The brother and his eyebrow were taken to Sutter Delta Medical Center, where a plastic surgeon re-attached it with 70 stitches, Aguinaga said.
Bouchard was arrested on allegations of mayhem and battery on a person. His bail has been set at $100,000, according to county jail records.
Aguinaga said investigators would be asking the district attorney's office to file charges of stalking as well.
Police have issued an emergency protective order for the wife should Bouchard post bail.
According to Aguinaga, Bouchard had no prior arrests or convictions for violent crimes, and his wife said he had never hit or kicked her. He had, however, allegedly slammed her against a wall, but she never reported it to police, the woman told police.