HAYWARD -- The Alameda County District Attorney's office Monday charged truck driver Carlos Mares with one count of felony hit and run for the death of Oakland motorcycle police officer Will Seuis last Thursday.

Mares, 38, also had been arrested on suspicion of vehicular manslaughter for the fatal accident on Interstate Highway 238 near East 14th Street, but Assistant District Attorney Tom Rogers said the California Highway Patrol hasn't finished investigating that charge.

The CHP is in the midst of doing a reconstruction of the accident in which Mares' big-rig allegedly hit Seuis' motorcycle, Rogers said.

Mares was to be arraigned on the hit and run charge this afternoon.

Rogers, who heads the DA's Hayward office, said he has instructed Deputy District Attorney Danielle London to ask Alameda County Superior Court Judge Ronni Maclaren to set Mares' bail at at least $500,000 because there is an immigration hold on Mares and he doesn't want Mares to be deported at this time.

Rogers said Mares has a social security number and a driver's license but there are questions about his citizenship status in the U.S.