Jeffrey St. Amour, 21, was arrested Tuesday evening by Palm Bay police for stalking young women for several months, police said.

Police said the investigation began last Friday when St. Amour emailed and texted a victim and her little sister from two different email accounts.

For three days, St. Amour asked one of the victims for nude photos or he would do violent things to her and her family, police said.

The victims told police they used to be friends with St. Amour, but had no idea he was the one sending the texts, police said.

Investigators said he sent penis pictures to the victim’s family, emails to her college saying that she wanted to attend the school for sexual reasons, and he threatened to place a bomb in her home as well as other threats.

A rock was thrown through the victim’s bedroom window on Friday about 3:30 a.m., and attached to the rock was a handwritten note saying she "had a nice bedroom," police said.

Several of the victim’s friends also received messages to tell the victim to look in her mailbox and outside her bedroom window. St. Amour is also accused of telling them he knew where the victim lived and if she didn’t send nude photos, he would harm her, police said.

“He sent a contract to the victim, 'if you sign this and send me the naked picture, I will leave you alone,’” said Cmdr. John Resh of the Palm Bay Police Department.

Police were called to the victim’s home at 10:30 a.m. Friday. St. Amour is accused of sending her text messages that said he knew police officers were there and that they couldn't save her.

Again, he demanded nude photos or he would send people to “take care of her,” according to the police report.

When St. Amour was questioned by police, he admitted to breaking the victim’s window with a rock, writing the notes, sending messages to the victim’s friends, and creating websites, emails and letters all because he was “bored.”

Police said the victim and her family were so scared, they had to leave their home. A police officer was hired to stand guard outside the home.

St. Amour was charged with aggravated stalking and possession of child pornography.

“We’ve identified three victims in this case and we suspect that there are more (suspects),” Resh said.

St. Amour was also charged with child pornography stemming from an incident in April.

A second victim received an email of a picture of male genitalia, which the victim ignored. However, that victim received more emails last Thursday demanding nude photos of herself, police said.

St. Amour is also accused of threatening to go to her home and harm her if she didn’t send nude photos, police said.

Police said St. Amour got his hands on nude photos of the victim, who was 16 years old at the time, and then sent them to her boyfriend. He threatened to send the images to the victim’s mother if she didn’t send nudes to St. Amour, police said.

St. Amour is also accused of setting up a fake Facebook account and posting the victim’s nude photos to the page.

During questioning by police, St. Amour admitted he received the photos from the victim’s ex-boyfriend and kept them. He decided to text the victim and upload the photos to a website because he was “bored,” police said.

A judge set St. Amour's bail at $600,000.