A Sparta man is in jail after allegedly threatening to kill a 17-year-old girl on Facebook.

Police say the man was arrested after he said he would send someone to slit the girl's throat.

The 17-year-old became friends with the man on Facebook through someone she knew at work.

It turned ugly when someone posted a negative message about a mutual friend of the two acquaintances on the social networking site. A heated cyber-argument ensued over several days, culminating Saturday when Angel N. Robles, 20, allegedly threatened to "send someone to slit her throat."

The father of the girl, who is a student at Sparta High School, saw the online threat and told police. Robles was arrested Monday and charged with a third-degree offense of making terroristic threats. He's being held on $7,500 bail and officials say a harassment change may be added.