A Harlem gang member — and brother of slain high- school basketball star Tayshana “Chicken” Murphy — was slapped Friday with a 50-years-to-life sentence for murdering a rival thug by a judge who told him “you don’t seem to think too well.”

Manhattan Supreme Court Justice Edward McLaughlin ripped Taylonn Murphy, 20, for not heeding several warnings to get on the straight and narrow — and out of the 3 Staccs gang.

“Mr. Murphy, you were warned not only by me, you were on probation,” McLaughlin said.

“A teacher, a coach . . . maybe other judges . . . and almost certainly the probation officer tried to communicate to you what would happen if you didn’t straighten out.”

In April, Murphy was convicted by a jury of fatally shooting Walter Sumter in 2011, just weeks after Sumter, 18, mocked his sister’s death in a rap video.