The 20-year-old gunman dies after a shootout with police during the attack at Umpqua Community College.
The college shooting is the latest in a series of US shootings, including at a Charleston church and Sandy Hook school.
Oklahoma has ordered an indefinite stay of execution for Richard Glossip and two other death row inmates.
Detectives are treating the 52-year-old officer’s death as a homicide but haven’t ruled out the possibility of suicide.
Officials in states already hit by heavy rain and flooding order preparations as they track Joaquin’s projected path up the coast.