Philadelphia rapper Cassidy is back in trouble with the law. The 'I'm a Hustler' MC was arrested Saturday afternoon (May 14) in Hackensack, N.J. for a probation violation, but that's only the start of his problems -- he's also a suspect in a murder and two attempted murders back in his Philly hometown.

Philadelphia police tipped off Hackensack authorities that Cass, born Barry Reese, had the open warrant for his arrest. Hackensack police officer Lt. Timothy Lloyd told NorthJersey.com that his Philadelphia counterparts forewarned him "to consider this person armed and dangerous," and this was a "high-risk warrant."

The extra care taken in arresting Cassidy likely stems from his having served an eight-month sentence -- he was released in March 2006 -- for charges that included involuntary manslaughter and aggravated assault for an incident in April 2005, which left two men wounded and Desmond Hawkins dead. The rapper has always proclaimed his innocence.

Cassidy is currently being held in the Bergen County Jail Annex as he waits extradition to Philadelphia to face the charges brought against him. The rapper's last album was 2010's 'C.A.S.H.' -- an acronym for Cass Always Stays Hard -- released via NBA superstar Carmelo Anthony's KrossOver Entertainment label.

Watch Cassidy's 'Drumma Bass'