In your game data folder you can find peds.ide file. 

Open it with Notepad++  and change one parameter:

Find Original line

254, BIKDRUG,  BIKDRUG , CIVMALE, STAT_CRIMINAL, man, 0,1, null,6,2,PED_TYPE_GEN,VOICE_GEN_BIKDRUG ,VOICE_GEN_BIKDRUG 

Change to this new 

254, BIKDRUG,  BIKDRUG, CRIMINAL, STAT_CRIMINAL, gang2, 110F,0, null,6,2,PED_TYPE_GEN,VOICE_GEN_BIKDRUG ,VOICE_GEN_BIKDRUG 

After change, save file. in notepad++ - File - Save