A pro scout for the Los Angeles Angels who calls himself “The Baseball Spy” was fired earlier this season after filming Colorado Rockies coaches on his cell phone while working in the stands.

The scout, Justin “Boomer” Prinstein, had only been hired by the Angels in December. He was let go shortly after the team was alerted to the incident by Major League Baseball, according to team and league sources briefed on the situation but not authorized to speak publicly.

Prinstein had been scouting the Rockies ahead of the Angels’ home series against Colorado from June 1-3. While seated in a section at Coors Field designated for scouts, he was spotted filming coaches on his phone during a game by a member of the Rockies organization. While scouts filming is generally considered a legal practice, using technology to steal or decode signs is not allowed.

The Rockies reported the incident to MLB, which alerted the Angels front office. Then-Angels general manager Perry Minasian fired Prinstein right away, multiple sources told The Athletic. Minasian also apologized to the Rockies front office, including president of baseball operations Paul DePodesta and general manager Josh Byrnes. Multiple sources briefed on the matter said that both organizations believe Prinstein acted on his own initiative and that the Angels are not facing any punishment from the league.

The Rockies won the series between the two clubs, which own the worst records in their respective leagues. The Angels declined to comment on the situation, and the team’s pro scouting director, Derek Watson, did not respond to a request for comment. The Rockies and MLB both declined to comment.

Prinstein did not respond to multiple interview requests via phone call, text message, email and his social media accounts. The 42-year-old, who owns the handle @TheBaseballSpy on X, locked the account following The Athletic’s attempt to speak with him on Friday.

He spent the past two years with two different Korean Baseball Organization teams and, according to his LinkedIn profile, as a consultant for Scouts Consulting Group LLC during the same time period. When The Athletic called the consultancy, a representative said no one with Prinstein’s name worked there, and a web page with his name and bio added to the group’s site in May 2025 is no longer active. Multiple messages for the Scouts Consulting Group founder went unreturned.

The Angels had added Prinstein’s position this season. According to the team’s media guide, the club employed five pro scouts in 2025, but six in 2026. Before his time with the Angels, Prinstein last worked for an MLB club in 2023 as an international scout with the Cincinnati Reds.

Before that, Prinstein wrote freelance articles and had a short-lived podcast called “The Baseball Spy.” The show had two episodes on iTunes, one of which talked about the Houston Astros sign-stealing scandal that rocked baseball in November 2019. Prinstein explicitly discussed the ban on recording technology, agreeing with his co-host that there was a “huge difference” between trying to steal signs legally with your eyes and Houston using a live camera feed and an audio cue to relay signs to players.

“It seems there needs to be a line drawn. And there is. There’s a (MLB) memo that went out. There’s a rule that says you can’t use technology,” Prinstein said. “To do this, it’s more like spying.”

It’s unclear who exactly Prinstein was filming on the Rockies, or for what purpose. Colorado was, at the time, calling pitches from the dugout — a practice that requires coaches to relay signs.

“They can try,” Rockies pitching coach Alon Leichman told The Athletic when asked in spring about teams attempting to steal signs. “It’d be absolutely hilarious if they tried.”

The Athletic spoke to scouts from four different organizations, all of whom said there’s no legal reason to film during a game since today’s televised broadcasts offer a plethora of angles and teams possess the technology to upload and analyze those as they see fit.

“If a guy goes to his glove a little bit more when he’s about to throw a cutter, we can see that,” said one American League scout, who spoke anonymously because he was not authorized to discuss the matter publicly. “So, unless you’re trying to cheat, there’s no good reason to have your phone out videoing. This isn’t 2014. Every team, even the Angels, has the technology to upload and analyze the broadcast.”

— Dennis Lin contributed to this report.