As I can see, there were some Halachic/Legal passages found in the Dead-see scrolls.
From the archeological and historical findings, I've understood that these sects kept Teffilin, Shabbes, Kashrus, Tevilah, sacrifices, Templaic works, Yom Kippur, the Three Regolim, and more. It's impossible that their Law didn't overlap the Pharisees' Mishnah in any Halacha.
Were any Mishnaic/Beraitah passages found in the Dead-sea scrolls?