The family member arrived at the home at about 3:45 p.m. and discovered the suspicious packages, police said.
Napa police came out to inspect the packages and requested the assistance of the Napa County Sheriff's Department bomb disposal team.
A robot was used to inspect the packages and a detonating device was used to render the packages safe, according to police, who say the contents of the packages were not explosive or hazardous.
The investigation into the incident is ongoing, police said.
Mehserle, who resigned last week, has been arrested and charged with murder for the Jan. 1 shooting death of Oscar Grant III, a 22-year-old Hayward man, at the Fruitvale BART station.
Mehserle is scheduled to be arraigned at 2 p.m. today at Wiley W. Manuel Courthouse.
