A Black family in Florida decorated the outside of their home with posters of their twin daughters to celebrate their graduating high school.
On Thursday, the family found an anonymous racist letter in their mailbox demanding the posters be taken down.
"Don't you think enough is enough? It's time to take those hideous posters of that ugly fat black girl down off your house," the letter read. "What a disgrace to the neighborhood. In fact, your entire brood is a disgrace to the neighborhood. Consider moving to a 'hood' of your kind. Your neighbors are watching you!"
The father, David Sproul, told NBC News in a phone interview Tuesday that he was shocked by the letter.
"I would say that was coldblooded because it was directed about kids. Even if it wasn't about race, to do something like that to a child, say something like that to children is terrible," he said.
Sproul said he and his family, including twin daughters Xanah and Xarah, have lived in the Timber Creek Plantation neighborhood in Yulee, about 25 miles north of Jacksonville, for five years and have never experienced anything similar.
Sproul's wife, Toya, shared the letter on her Facebook page calling the anonymous writer a "coward."
"Racism is alive but we ain't scared!!!! This showed up in my mailbox today," she wrote in a post on Thursday.
Sproul said he let his daughters read the letter when they got home later that day, and the girls "didn't let it bother them."
"They realized that the person who wrote it didn't even know them, so they kind of disregarded it instantly," he said.
The family filed a police report with the Nassau County Sheriff's Office. A spokeswoman for the department said the incident is being investigated.
“We at the Nassau County Sheriff’s Office do not tolerate racism and hate crimes in our county," Undersheriff Roy Henderson said in a statement. "This is out of character for Nassau County and we will continue to investigate this incident. We are proud of the Sproul twins’ accomplishments and hope to get to the bottom of this soon.”
The family isn't letting the letter dampen their pride in the twins' achievements.
Xanah and Xarah, who both want to be doctors, will be attending Saint Leo University in Florida for the pre-med program, Sproul said, adding that they have both received scholarships from a local program they were involved with.
"Although they are very accomplished young ladies and they do work very hard ... at the same time, this didn't happen to two accomplished young women. This happened to two young Black women," Sproul said. "The person who did this didn't know that they had any accomplishments, didn't know their work ethic in any way. This happened to two humans, and it shouldn't have happened at all."
A drive-by parade is planned for Xanah and Xarah on Thursday, according to a Facebook event page that has drawn over 360 responses. And Sproul said the family has received supportive messages from people all over the world, including in the Netherlands, Ireland and New Zealand.
"The positivity that came out of something so negative is really good to see," he said.