IRVINE, Calif. (NEWS1130) – A $1 million reward has prompted numerous tips to authorities seeking a fired Los Angeles police officer suspected of killing three people.

Los Angeles police Lt. Andrew Neiman says well over 600 clues are being investigated as of Monday morning.

Police have been searching for Christopher Dorner since last week and are protecting dozens of families considered targets based on his Facebook rant against those he held responsible for ending his career with the LAPD five years ago. Among those Dorner, 33, is suspected of killing is a police officer.

The ranks of the LAPD have been stretched thin by the hunt. The department has been on tactical alert since Sunday, which means officers are staying on duty beyond their shifts.