A California man allegedly took on the guise of accused Parkland shooter Nikolas Cruz to taunt, threaten, and stalk the loved ones of Cruz’s victims online—during the first Christmas holidays since they were killed.

For nearly three weeks from late December into January, Santa Ana resident Brandon Fleury allegedly bombarded family and friends of those killed in last year’s massacre at Marjory Stoneman Douglas High with messages like, “I killed your loved ones hahaha” and “I gave them no mercy” on Instagram. He used multiple Instagram accounts—including one with the username “nikolas.killed.your.sister.”—to mock and threaten the family and friends of the victims multiple times a day, prosecutors say.

According to a criminal complaint filed Friday in the Southern District of Florida, Fleury repeatedly tagged them in posts to remind them of their loss, "cheering the deaths of their loved ones," and at one point even threatened to kidnap them while posing as Ted Bundy.

Fleury allegedly singled out the father, brother, and best friend of 14-year-old shooting victim Jaime Guttenberg, teacher Scott Beigel, who was killed trying to help students, and the loved ones of another unnamed victim who was gunned down on Valentine’s Day last year when Cruz entered the school with an AR-15 style rifle.

“With the power of my AR-15, I erased their existence,” Fleury allegedly wrote in an Instagram post from Dec. 22, accompanied by a smiley face, applause, and handgun emoji.

“They had their whole lives ahead of then and I fucking stole it from them,” he wrote in another, according to prosecutors. “Did you like my Valentines gift? I killed your friends.”

In total, Fleury allegedly used 10 different Instagram accounts to harass the loved ones of Parkland victims in posts multiple times a day. Some of the accounts had usernames like: “nikolasthemurderer,” “The.douglas.shooter,” “Nik.taunts_,” and “Bullseye.taunts.and.teases.”

From some of these accounts, Fleury is accused of making direct threats against his targets. On Christmas, he allegedly used a “teddykillspeople” account to make kidnapping threats while posing as serial killer Ted Bundy.

“I’m your abductor,” he allegedly wrote, with a smile and applause emojis.

On Jan. 9, Fleury also implied that he would wield an AR-15 against them.

“With the power of my AR-15, you all die,” he allegedly wrote from “the.douglas.shooter” account.

Upon the threats of kidnapping and murder, Instagram voluntarily gave up the IP address to “the.douglas.shooter” account to law enforcement—which was determined to be owned by Fleury’s father. According to the complaint, a search warrant was executed on Fleury’s house on Jan. 16. When law enforcement entered, he allegedly told his father authorities were there because of “some stupid shit” he had done online.

When talking to law enforcement, Fleury allegedly maintained that he was trolling victims' loved ones and wanted to “get reactions” from them. He also told officials that he had a “fascination” with Cruz, Ted Bundy, and other mass shooters and serial killers.

Fleury is also said to have admitted he targeted the loved ones of Parkland victims because they were “activists” and had large social media followings—which would aid in his goals of “gaining popularity and notoriety.” When authorities told him how mentions of kidnapping and shooting with an AR-15 could be seen as threats, Fleury allegedly responded, “I guess so.”

Fred Guttenberg, the father of Jaime Guttenberg who became outspoken on gun control in the wake of the deadly rampage, told The Daily Beast that he was “thankful for the work of law enforcement on this.”