A 19-year-old man has been arrested in connection with several crimes related to the sexual assault of a minor in Portola Valley, according to the San Mateo County Sheriff's Office.

The man was arrested on suspicion of lewd acts with a child under 14 years old, oral copulation with a child under 14 years old, sexual intercourse with a minor and furnishing harmful matter to a minor, according to the Sheriff's Office.

In August, sheriff's office detectives began investigating a report of a sexual assault case involving a minor under the age of 14 that occurred on July 1.

Deputies said the investigation produced information and evidence that the man allegedly sexually assaulted the victim in the suspect's home in Portola Valley.

The 19-year-old was arrested on Thursday in San Mateo.

Deputies said the investigation is ongoing, and the assault is believed to have been an isolated incident.

Editor's note: It is The Almanac's policy to withhold the names of those arrested for most crimes until the District Attorney's Office has determined that there is sufficient evidence to file charges in the case.