Employees at Massage Envy, located on the 12300 block of Seal Beach Boulevard, on Sunday found a broken window and graffiti, including a swastika and the words "happy ending."
The damage is estimated at about $1,500. Nothing was stolen.
An employee Halloween party was held at the business Saturday night, which ended at 10 p.m. The crime happened sometime after.
Authorities say at this time the incident does not meet the California Penal Code requirements of a "hate crime" because the victims are "not associated with any actual or perceived characteristics listed in the crime."
Anyone with information about the incident was asked to contact Seal Beach police at (562) 799-4100.