Investigators said disclosures from victims date back to at least 2012, leading detectives to believe additional victims and witnesses may still be out there.
According to the Monterey County Sheriff's Office, Marchica was serving as a pastor and regularly offering religious services at a community gathering center in the Hidden Valley community of San Benito County at the time of his arrest.
Authorities did not identify the congregation or organization.
Detectives also said Marchica previously owned bakery businesses in Prunedale and Monterey, as well as gyms in Sand City, Seaside and Prunedale, where he offered physical therapy, massage therapy services and worked as a Jiu-jitsu instructor.
Investigators believe those community connections may have put him in contact with additional potential victims over the years.
Marchica was booked into the Monterey County Jail on multiple felony charges, including lewd or lascivious acts with a child, sexual penetration of a child, oral copulation with a child and annoying or molesting a child.
His bail was set at $17.5 million.
The sheriff's office is urging anyone who may have been victimized by Marchica or anyone with information that could assist the investigation to contact detectives.
"Detectives understand that victims of sexual abuse often delay reporting for many years," the Monterey County Sheriff's Office said in a statement. "Regardless of when the abuse may have occurred, investigators encourage victims to know that they will be treated with dignity, compassion, and respect throughout the investigative process."
Anyone with information is asked to contact Detective Janelli Arroyo at (831) 755-7261 or Detective Sgt. Nicholas Kennedy at (831) 755-3773.