NATCHEZ — A third suspect has been arrested in connection with a child molestation investigation involving 3-and 4-year-old sisters.

Nolan Morrison Jr., 21, was arrested Saturday by the Adams County Sheriff’s Office and charged with one count of sexual battery.

He is being held at the county jail on a $50,000 bond.

The two girls are believed to have been assaulted by a group of three men on two separate occasions, Adams County Sheriff’s Office Investigator Ricky Stevens said.

Last week Terry Holmes, 48 and Parnell McBride, 23, were arrested, and each was charged with two counts of sexual battery.

Adams County Sheriff’s Deputy Maj. Jody Waldrop said the investigation revealed it was appropriate to charge Morrison with only one count of sexual battery.

Authorities became aware of the alleged crime when the older sister told her mother of an October 2008 incident in which she and her sister were assaulted.

Holmes is being held on a $150,000 bond and McBride, who was on bond for an unrelated incident, is not eligible for bond.

Stevens said the investigation is still ongoing.