Albany Juan "Killa" Anderson said he does not know why he plunged a knife into the neck of 15-year-old Adeujuan Adams on May 25, 2012, a wound that eventually took the teenager's life.He will have 18 years to think it over. An Albany County Court judge sentenced the reputed South End gang member to 18 years in prison Thursday for stabbing Adams during a 9:30 p.m.