Police arrested a Columbia man Wednesday morning for allegedly harassing his ex-girlfriend.

Officers arrested Nathaniel Cass, 24, after he allegedly sent threatening messages to his ex. Police say Cass sent more than 100 messages in 75 minutes to a woman, causing her to fear for her safety.

Cass was arrested for harassment and third-degree domestic assault. He posted a $1,500 bond and was bailed out of the Boone County Jail.