Richard Heverly, of La Verne, was placed on paid administrative leave following his Aug. 10 arrest in Riverside County.
He returned to work at the jail's transportation division on Nov. 4, said sheriff's spokeswoman Cindy Beavers.
At about 6:30 p.m. on Aug. 10, tow-truck driver Roger Gilstrap saw a big-rig truck on fire on the 10 Freeway near Eagle Mountain Road, about 50 miles east of Indio.
Gilstrap positioned his truck to block off lanes affected by the burning big rig and called the California Highway Patrol from his cell phone, according to the arrest declaration in Heverly's court file.
While Gilstrap was on the phone with the CHP, Heverly, 42, pulled up beside him in a red Dodge truck.
Heverly flashed his sheriff's department badge and told Gilstrap, "This entitles me to do whatever the (expletive) I want," according to the arrest declaration, which was written by a CHP officer.
Heverly grabbed Gilstrap's cell phone and disconnected the call, then pulled Gilstrap out of the tow truck and handcuffed his right hand, bruising and injuring Gilstrap's wrist, according to the arrest declaration.
Heverly then drove the barrel of a handgun into Gilstrap's ear, and told him, "I have a gun in your ear and I will kill you," according to the arrest declaration.
Heverly twisted the gun into Gilstrap's ear, bruising and cutting the inside of Gilstrap's ear and the surrounding area, according to the arrest declaration.
Heverly then handcuffed Gilstrap's arms behind his back and led him to the passenger side of the truck. He held Gilstrap for 3 to 5 minutes, according to the arrest declaration.
Heverly never told Gilstrap the reason for handcuffing him, according to the arrest declaration. Gilstrap told officers he feared for his life during the encounter with Heverly.
Heverly has pleaded not guilty to four felony charges: assault with a semi-automatic firearm, assault by a public officer, criminal threats and false imprisonment. All four charges carry sentencing enhancements because Heverly used a gun.
San Bernardino County sheriff's spokeswoman Cindy Beavers declined to discuss the reason that Heverly was allowed back to work at West Valley Detention Center.
Such details, Beavers said, "are never disclosed because we are not at liberty to discuss any of the findings in an administrative investigation."
Beavers said the decision to place a deputy on administrative leave is made on a case-by-case basis.
"When it is contrary to the best interests of the department for an employee to continue his regular duties, he may be assigned to special duty leave with pay at the discretion of the office of the sheriff," Beavers said.
Beavers said she wasn't aware of any restrictions placed on Heverly while he is off duty, such as restrictions on his permission to carry a gun.
Michael Schwartz, Heverly's Santa Monica-based attorney, said "there's much more to this case than the probable cause declaration."
He declined to comment on the specific allegations against Heverly.
Schwartz also represented Ivory Webb, a former San Bernardino County sheriff's deputy who was acquitted of criminal charges filed after he shot off-duty Airman Elio Carrion in Chino in 2006.
Heverly is next scheduled to appear in Indio Superior Court on Dec. 23 for a felony settlement conference. A preliminary hearing in the case is scheduled for Jan. 6.
At a preliminary hearing, the prosecution must present sufficient evidence for each charge against a defendant to be brought to trial. Preliminary hearings typically include testimony.