A six-month multiagency investigation dubbed "Casper" has culminated with the seizure of more than 100 firearms, and 11 people now facing state and federal charges.

Law enforcement officials gathered Thursday at the Westchester County Police Academy in Valhalla to tout the teamwork that resulted in the massive confiscation of illegal weapons.

Police say almost half of the firearms are so called "ghost guns," or guns without serial numbers that are untraceable and often assembled at home.

Other items seized included rifles and high-capacity drum magazines.

Police say they executed eight search warrants at eight different locations this week in Westchester, including Harrison, Yorktown and New Rochelle.

Officials vow they are going to be relentless in cracking down on illegal guns in their communities. "What this means is that we're actively pursuing all of the illegal firearms in the county of Westchester and beyond," says Westchester County Deputy County Police Commissioner Terrance Raynor.

The Westchester County DA says the top state charge the suspects are facing is criminal possession of a weapon, which carries a maximum of 25 years in prison.