The woman left her ex-boyfriend, who is the father of her two children, and moved into her parents' house with her children on Thursday, police said.
On Friday, the woman began chatting with her ex-boyfriend, a Waipahu man, on a social networking site, but the chat escalated when the man allegedly threatened her, her children and family members.
The woman filed a report with another law enforcement agency and on Saturday, Honolulu police said the suspect called the woman at 4:45 in the morning and harassed her.
Police located the suspect at about 8:30 a.m. and arrested him in Waimanalo for outstanding warrants. While he was being processed, police found the other cases and arrested him for terroristic threatening and harassment. He was charged and cited for terroristic threatening in the second degree and harassment on held on $2,000 bail.