The police investigation into the murders of rapper G$ Lil Ronnie and his 5-year-old daughter in the Fort Worth, Texas area has hit a major break … cops say they know who is responsible, and they’re calling the suspects straight-up punks!!!

The Forest Hill Police Department held a press conference Wednesday and identified Adonis Robinson and Jakobie Russell as the suspects — Police Chief David Hernandez called them both cowards and “public enemies” … and pointed out Robinson’s sex-offender past.

The two Texas natives are said to be on the run, scared and afraid to face the music … but Hernandez vowed police will catch them.

The two suspects are accused of staking out Ronnie and little R’Mani at a Slappy’s Car Wash in Forest Hill Monday, before firing off dozens of rounds … killing the girl and then chasing down Ronnie to finish him off.