Investigators have arrested a man suspected of stalking more than 15 women on various social-media platforms and threatening some with violence, according to the Orange County Sheriff’s Department.

Dominic Luis Magdaleno, 25, of La Habra, was booked into Orange County Jail on suspicion of felony stalking, felony witness intimidation, and felony criminal threats. He was being held on $500,000 bail.

Magdaleno was arrested Thursday, Dec. 7 at the La Habra Public Library.

Investigators were alerted to the suspect’s activity after a 19-year-old woman came forward and reported he had been harassing her on Instagram, Jaimee Blashaw, a Sheriff’s Department spokeswoman, said in a statement.

A six-month investigation shows that Magdaleno, using Twitter, Instagram and Tumblr, allegedly stalked, harassed and threatened females, Blashaw said. In some cases, Magdaleno is suspected of threatening to sexually assault, rape and even kill the victims, she added.

Investigators are attempting to determine if there are possibly other victims and ask anyone with information to contact the Sheriff’s Department at 714-647-7000. Anonymous tips may also be submitted to the Orange County Crime Stoppers at 855-TIP-OCCS.