oscar hernandez jr has pleaded guilty to transporting firearms , obstruction of justice , lying to a federal grand jury and witness tampering .
confessed to shipping aaron hernandez three weapons a month before odin lloyd 's killing june 2013 .
hernandez jr said he was blinded by new england patriot 's fame and ` grateful to be noticed '
aaron hernandez has been convicted of first-degree murder and sentenced to life in prison without parole .