Man of the cloth: Rabbi Avraham Berkowitz, shatnez checker

Rabbi Avraham Berkowitz, is a trained “shatnez checker.” His expertise — in Torah and textiles — ensures that the Torah prohibition against mixing wool and linen in the same garment is observed thread by potentially offending thread.
The eighth-grade teacher at Hillel Academy examines clothing with the zealousness of a Sherlock Holmes in pursuit of a murderer — except Berkowitz’ mission is fulfilling G-d’s law.
Shatnez first appears in Leviticus 19:19, then in Deuteronomy 22:11 — passages prohibiting the mixture of wool and linen in the same garment, the blending of different species of animals and the planting of different kinds of seeds together. This prohibition of mixtures is known collectively as kilayim.
The laws of shatnez “are chukim,” says Berkowitz, 46. “Some laws in the Torah are logical, and some are not. There’s no logical reason why we can’t mix wool and linen together.