Three people were arrested after Michigan State Police discovered a "Tommy gun" among several firearms and crystal methamphetamine during a drug bust in Isabella County. 

While serving a search warrant at a home in northern Isabella County, detectives with MSP's Multi-jurisdictional Intelligence and Narcotics Task Force, as well as members of other law enforcement agencies, found 56.9 grams of crystal methamphetamine and seven long guns, including a "Tommy gun," police said. 

Two suspects were arrested on warrants for delivery of crystal methamphetamine, police said, while a third suspect was taken into custody on an unrelated warrant. 

An investigation is ongoing.