Officers went to Harbor Boulevard and Walnut Avenue at about 4:40 a.m. after someone called 911 to report finding a person who had been stabbed, according to the Fullerton Police Department.
"Upon arrival, officers located a ... 20-year-old male Hispanic victim with a stab wound on the pedestrian bridge crossing over Harbor Boulevard," police said in a statement.
Information was not immediately available on the identity of the fatally wounded man.
"At this point in the investigation, the motive is not yet known, or whether it is gang-related," police said.
Anyone with information on the case was urged to call police at 714- 738-5334, or contact Orange County Crime Stoppers at 855-TIP-OCCS or www.occrimestoppers.org.
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