Republican gubernatorial nominee Doug Mastriano cut his interview with congressional Jan. 6 investigators short on Tuesday and pledged to challenge the committee in court, multiple outlets report.

Mastriano — who boosted efforts to overturn the 2020 election, was outside the U.S. Capitol on Jan. 6, and backed efforts to submit alternate, pro-Trump electors for Pennsylvania — didn't answer any questions amid an impasse over ground rules, a source familiar with the matter told CNN.

The virtual appearance lasted 15 minutes in all. Mastriano and his attorney, Tim Parlatore, had asked to independently record the deposition, a condition the investigators were unlikely to agree to. They also challenged the legality of the subpoena that was issued for his testimony in February.

"We're happy to provide the information if they can either do it fairly and legally or if we can reach a resolution on how to do a voluntary interview which minimizes the risk of election interference," Parlatore said.

Trump's secretary of state, Mike Pompeo, was also due for a virtual, closed-door deposition before the investigators on Tuesday. 

THE CONTEXT: Politico reported in June that Mastriano had agreed to the interview and turned over requested documents. But because of a sizable carve-out exempting materials related to his official actions as state senator, the documents submitted were mostly public social media posts.

Mastriano's involvement in efforts to overturn the 2020 election is well-documented. According to timelines from The Inquirer and WHYY, he joined strategy sessions at the White House, amplified conspiracy theories in Gettysburg, introduced a bill that would reject Pennsylvania's election results, and used campaign funds to send supporters to D.C. on Jan. 6. 

Democrats have seized on those efforts in this year's high-stakes governor's race, with Mastriano — who handily won May's primary in a crowded GOP field — making the elimination of mail voting and other election policy changes a central plank of his platform.

Mastriano has also chosen the person who would serve as the state's chief elections officer if he's elected, but he hasn't revealed their name.

» TALK OF THE TOWN: On Friday, Aug. 12 at 6 p.m. ET, meet our new State College regional bureau team, get an inside look at what we're investigating, and tell us how we can better connect with you. RSVP here. Tell us what you want to know about the bureau at events@spotlightpa.org. 

PARTY OFF: Philly police denied more than 200 block parties this year for "criminal activity" amid a decade-long block party decline. But they won't say how they decide which permits to cancel, Billy Penn reports. 

LYME VACCINE: Pennsylvanians are among the volunteers signed up to test the first potential vaccine against Lyme disease in 20 years, CBS News reports. Robert Terwilliger of Blair County was the first in line.

OPEN CALL: Director Ethan Coen (No Country for Old Men; O Brother, Where Art Thou?) wants you for his next movie. An open audition is coming to Pittsburgh, via Beaver County Times. No acting experience necessary.

PEEP THIS: The New York Times endorses your use of Bethlehem-made marshmallow Peeps in your campfire s'mores.

FALL GUIDE: Twenty "hidden waterfalls" located across Pennsylvania aren't hidden any more thanks to the state's tourism office.