Soulja Boy Kidnapping Case Rejected

Soulja Boy won't be charged for allegedly kidnapping a woman and tying her to a chair in his garage ... because prosecutors have rejected the case.

The Ventura County District Attorney tells TMZ ... they're declining to file charges against the rapper due to insufficient evidence. The alleged victim accused Soulja Boy of holding her captive for 6 hours, but our law enforcement sources say a police investigation didn't prove it.

TMZ broke the story ... a woman went to police back in February claiming Soulja kidnapped her, held her captive in his garage and tied her to a chair with an extension cord. Soulja denied the allegations, and his team said the woman was flat-out lying.

The Ventura County Sherriff's Department served a search warrant at Soulja's home and looked for evidence of a kidnapping ... and that turned out to be a huge problem for Soulja, for entirely different reasons.

Sheriffs say they found ammo on the property, which is a violation of Soulja's probation for a weapons case in L.A. County dating back to 2014 ... so he was later arrested for that.