San Bernardino police later confirmed the package, received in the 1400 block of east Victoria Avenue from a Sears company, appeared to pose no threat.
The package initially went out with driver Selena Esparaza until she realized to whom it was addressed and returned it to the distribution center.
"I saw it was the shooter and wanted no part of it," she said.
Esparaza described the box to be medium-sized and employees at the facility notified authorities as a precaution.
A bomb technician from the San Bernardino County Sheriff's Department and other law enforcement officials investigated the package that turned out to have a few items of clothing.
Workers at the facility self-evacuated, and operations were temporarily suspended but later resumed to normal operations.
The package alerted authorities as it was addressed to Syed Farook and Tashfeen Malik's Redlands home in the 50 block of North Center Street, where pipe bombs, explosives and over 3,000 rounds of ammunition were found.
Item was safe, posed no threat.— Chief Jarrod Burguan (@SBPDChief) December 5, 2015
Call at UPS is an abundance of caution. Package with delivery address to suspect res in Redlands. Isolating package to be safe.— Chief Jarrod Burguan (@SBPDChief) December 5, 2015
Driver realized it was the same address and returned to facility with the package.— Chief Jarrod Burguan (@SBPDChief) December 5, 2015