The Uvalde, Texas, school shooter used livestreams on a social media app to spew threats against girls who rejected him.

The gunman, who turned 18 the week before the rampage that saw him kill 19 children and two adults at Robb Elementary School, was a prolific user of an app called Yubo. The Washington Post said Yubo has been downloaded more than 18 million times in the United States and likened it to a “Tinder for teens.”

Yubo users whose names were withheld shared messages with The Sun, including one in which the shooter told someone who rejected him, "You're going to regret not doing what I say.”

A female Yubo user told The Sun that the shooter “would tell people to lock their doors, don’t show up to school tomorrow, just classic s*** that creeps on the internet say. I never knew it would manifest into this.”

“The threats were mostly toward women in response to them rejecting him," she said.

“He would threaten to rape girls. He would always say he had the power to make us go missing. It was honestly just typical stuff you hear on apps like Yubo and Discord, etc., just creeps you have to ignore,” she said.

In the Post’s review of the shooter’s Yubo activities, it quoted a 16-year-old boy in Austin, Texas, who said the shooter frequently lashed out.

“I witnessed him harass girls and threaten them with sexual assault, like rape and kidnapping,” he said. “It was not like a single occurrence. It was frequent.”

He said the conduct was reported to Yubo, but he did not think anything was done.

The Yubo user who spoke to the Sun said the shooter let his hatred flow freely online.

“He was an extremely homophobic, transphobic and racist individual, which of course resulted in him using slurs, and he openly admitted his homophobia multiple times," she said.

“He had a video in his profile with the caption ‘When the teacher doesn’t let me use the bathroom,’ and the man in the video goes on to use degrading language against black people,” she said.

The girl said she shared the information she has because of the Uvalde incident.

“The whole reason for me sharing this is because the community on Yubo saw how little information anyone had on him, and we realized just how much we knew about him,” she said.

“I have messages from him from early this year. He was around us all for a long time There’s sides to Yubo, different communities, where everyone is familiar by name and everyone is mutual friends with each other. We all knew him. We just never thought to record the things he said as they were being said,” she said.

Yubo issued a statement in response to the allegations.

"We are deeply saddened by this unspeakable loss and are fully cooperating with law enforcement on their investigation,” the statement said.

"At this stage, we are not legally able to release any specific user information outside of direct requests from law enforcement but can confirm that we are investigating an account that has since been banned from the platform,” the statement said.

This article appeared originally on The Western Journal.