Family of NYC bartender stabbed to death in ‘gut-wrenching’ attack rips ‘coward’ boyfriend at his sentencing

The crazed boyfriend who fatally stabbed his Queens bartender gal pal was sentenced Friday — as the victim’s family ripped the heartless killer as a “pathetic coward” who took away a “beautiful” soul. Marcin Pieciak, 37, was sentenced to 24 years in prison for the brutal attack in which he stabbed his Irish girlfriend Sarah…