* Correction appended. 

Democratic gubernatorial candidate Andrew White is divesting from a company he owns that has been criticized as a "border security business," the latest development in a drama-filled stretch of his runoff against former Dallas County Sheriff Lupe Valdez.

White, the son of former Texas Gov. Mark White, announced Tuesday he would divest from the company, Geovox Security, if he wins the runoff. That drew a critical response from the campaign of Valdez, who is looking to bounce back from a shaky appearance at a town hall over the weekend that caused her to lose an endorsement to White.

"Just days ago, Andrew White was saying owning a company that benefits from a militarized border is a 'perfect' example of the type of leadership he wants to bring as governor," said Juan Bautista Dominguez, a spokesman for Valdez. "Now that he has new friends, he says he would divest 'if he wins.' If he thought it was truly problematic, he would divest now, stay divested, and not wait."

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White responded on Twitter, saying the sale of Geovox, a company that uses heartbeat-detection technology to find people hiding in vehicles, is "underway." But he said it won't happen before the May 22 runoff date. 

Valdez was the leading vote-getter in the March primary, but she has faced a tough couple of days. On Sunday, she struggled to explain her record as sheriff at the town hall, which was organized by a group of young Latino activists, particularly when it came to her department cooperating with federal immigration authorities. 

The group, Jolt Texas, subsequently endorsed White, though they still had reservations about his involvement in Geovox and hoped he would cut ties with it down the line.

In his tweet, White tried to return the focus to the forum and the issue of whether Valdez will debate him. White has been pushing for a debate since the runoff began, and Valdez's campaign has said it is open to debating but has not committed to anything.

"What can happen before the runoff is a debate," White wrote. "Lupe wasn’t able to answer an 18-year-old’s question about her record. What other questions will she avoid?"

White said at the forum that his company's technology is put to use on the U.S. border and in other countries "to make sure that sex trafficking is not happening, to make sure that if there are people in the back of that truck, they're not dying from heat exhaustion or dehydration." White characterized it as "smart security" that stands in contrast with Republican efforts to secure the border, which most recently included ratcheting up the National Guard presence there at the direction of President Donald Trump.

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"It's a perfect example, in my opinion, of the type of leadership I want to bring to the border, which is yeah, we need a secure border, for sure, it's our sovereign right, but we should have a smart border, not a fear-mongering border," White said. "I’m sure this issue might be used against me — that I have a quote 'border security business' — but the reality is it’s used to protect people’s lives, and frankly I’m very proud of the fact that in the 20-something-year history that we’ve had, we have saved thousands of lives with this technology."

White's promise to divest from Geovox if he wins was first reported by The Dallas Morning News.

Correction: Due to an editing error, an earlier version of this story attributed a quote by a Lupe Valdez spokesman to the candidate herself.