Los Angeles detectives hunting a former policeman accused of murder say they have received hundreds of tip-offs after offering a $US1 million reward for his capture.
Christopher Dorner has been charged with one killing and is suspected of carrying out two others as part of a campaign of revenge against his former colleagues.
The 33-year-old was dismissed from the Los Angeles Police Department (LAPD) five years ago.
Los Angeles police Lieutenant Andrew Neiman said officers were following up on more than 600 tips as of Monday morning, the BBC reports.
One of those killed was Monica Quan, 28, who was gunned down along with her fiance in her car on 3 February in Irvine, California.
Her father, Randal Quan, is a retired police captain who represented Mr Dorner in a disciplinary procedure.
Police are protecting 50 families, many belonging to former LAPD colleagues, against whom Mr Dorner has vowed revenge for ruining his career.