San Bernardino County Sheriff's Deputy Nathan Gastineau was arrested last week. The 30-year old is accused of having a sexual relationship with a 16-year-old girl.
Deputies said while they were investigating the allegations, they discovered another man also was having a sexual relationship with the same girl.
Jason Anguiano, 27, Rialto, was arrested on Monday and released on bail. Authorities said he does not work for the sheriff's department.
