The paint has since been cleaned off, but a large piece of plywood covering the broken glass remains.
The suspect may have left an identifying clue, police said. The vandal wielded spray paint, leaving the tag 'snip,' which may be the vandal's calling card.
"I feel that someone needs to do something about it," said Diana Warren, who drove by the memorial. "Maybe protect it in some way."
Police are reviewing surveillance video.
Related
This isn't the first time a memorial dedicated to veterans has been defaced in San Jose. The Sons of San Jose monument honoring veterans of the Vietnam war was defaced last summer.
Mike Salas, a veteran himself, told KPIX-5 the incident is heart-breaking.
"My immediate thoughts are with the families and the ones who went to foreign lands and shed their blood and never came home. Anybody with a heart would have never touched a memorial like that," he said.