We spoke with multiple realtors representing homes in Bethel Park, PA -- the hometown of the would-be-assassin -- and they've painted a bleak picture in the aftermath of Saturday's shooting.

For instance, realtor Kristy Kaslewicz tells TMZ ... she has had zero showings since the attack. While she couldn't say for sure the shooting has directly impacted her business, she's suspicious, especially because law enforcement has barricaded the block leading up to Thomas' parents' home.

She adds ... "Up until that day, I had 2-3 showings a day at my listing in Bethel Park, only a few blocks from the shooter’s parent’s home. Since then, I haven’t had a single scheduled showing."

Susan Deely, another realtor in the area, has expressed a similar sentiment ... telling TMZ the market has become really "stagnated" amid the shooting tragedy, which injured the former prez and killed 1 person in the crowd.

Susan says it's been even harder to sell properties this week ... and that's on top of some very real market struggles before last weekend. She's waiting out the drama, but says still "no bites" to report.

Realtor Michael Pohlot faces a similar problem, especially since he has a listing near the shooter's parents' home -- and says he isn't getting any formal offers, even though there are a couple of interested parties.

He's maintaining an optimistic outlook, however ... telling us Bethel Park is more than the Trump shooter's hometown -- it has a great school system, shopping and proximity to Pittsburgh.