What to Know About How Wildfires Form, Intensify and Spread | A North Korean Hacker Tricked a US Security Vendor, and more

F.B.I. Examining Bullet Fragments Found at Trump Rally Site  (Adam Goldman and Glenn Thrush, New York Times)
The F.B.I. is examining numerous metal fragments found near the stage at a campaign rally in Butler, Pa., to determine whether an assassin’s bullet — or potential debris — grazed former President Donald J. Trump’s head, bloodying his ear, according to the F.B.I. and a federal law enforcement official.
The bureau has asked to interview Mr. Trump as part of its broader investigation, hoping to provide insights into the shooting and possibly a more complete record of his injury, the official said, speaking on the condition of anonymity to discuss the continuing inquiry.
Unanswered questions about the object that struck the Republican nominee for president have lingered since the shooting on July 13, with Mr. Trump claiming that he was struck by a bullet — and casting his survival as an act of divine intervention.
F.B.I. officials have been more circumspect, citing the need to analyze the evidence before determining what struck Mr. Trump — a bullet, metal shard or something else.
It is not unusual for the type of bullet that Mr. Crooks fired from his AR-15-style semiautomatic rifle to tumble end over end and break apart after hitting even a small solid object. Gun experts say a fragment might, for instance, have hit a metal stanchion.
Still, a bullet could have grazed Mr. Trump’s ear, and the F.B.I. has not ruled that out. Investigators found eight rifle casings on the roof where the shooter was positioned.
It is not clear if investigators have eliminated other potential sources of debris. But bureau analysts appear to be focused on metal fragments, as opposed to glass from the teleprompters onstage. Photos of the teleprompters next to Mr. Trump show they were intact after the bullets were fired.
F.B.I. analysts are also examining still images and other electronic evidence for clues.
Gun experts said the F.B.I. could rely on trajectory analysis, a physical examination of any linked bullet and the president’s wound to possibly figure out what happened. A detailed analysis of bullet trajectories, footage, photos and audio by The New York Times strongly suggests Mr. Trump was grazed by the first of eight bullets fired by Mr. Crooks.

How Some States Are Making It Harder to Register Voters  (Michael Wines, New York Times)
The political right has long sought to winnow voter rolls in the name of stopping fraud, including a stream of challenges this year. As Democrats prepare for a sprint to capitalize on the excitement of a new presidential ticket by signing up new voters, they are finding entirely new barriers in Florida and some other states to the sorts of voter registration drives that have been a campaign staple for both parties.
The Florida law imposes new regulations, with criminal penalties for violations, on groups that sign up new voters and deliver the collected applications to election officials. For example, it allows fines of up to $2,500 if a registration form delivered to election officials contains a mistake. If a registration drive allows people with certain felony convictions to sign up new voters or handle registration applications, the fine could rise to $50,000.
The Florida League of Women Voters and other groups sued in federal court to block the law last year, and a trial was held this spring. A ruling is expected soon.
Laws similar to Florida’s have been passed recently by a number of Republican-controlled state legislatures, although none of the states are battleground states in this year’s election, so the restrictions on voter registrations are unlikely to affect the presidential election.

A North Korean Hacker Tricked a US Security Vendor into Hiring Him—and Immediately Tried to Hack Them  (Wired)
KnowBe4, a US-based security vendor, revealed that it unwittingly hired a North Korean hacker who attempted to load malware into the company’s network. KnowBe4 CEO and founder Stu Sjouwerman described the incident in a blog post this week, calling it a cautionary tale that was fortunately detected before causing any major problems.
“First of all: No illegal access was gained, and no data was lost, compromised, or exfiltrated on any KnowBe4 systems,” Sjouwerman wrote. “This is not a data breach notification, there was none. See it as an organizational learning moment I am sharing with you. If it can happen to us, it can happen to almost anyone. Don’t let it happen to you.”
KnowBe4 said it was looking for a software engineer for its internal IT AI team. The firm hired a person who, it turns out, was from North Korea and was “using a valid but stolen US-based identity” and a photo that was “enhanced” by artificial intelligence. There is now an active FBI investigation amid suspicion that the worker is what KnowBe4’s blog post called “an Insider Threat/Nation State Actor.”