A 19-year-old Scotch Plains man, whom police say has been entering unlocked cars in a high school parking lot and taking wallets, jewelry and other valuables, was arrested Saturday during the Essex County Basketball Tournament.

William Rivera was pulled over and arrested before leaving the West Essex Regional High School parking lot after police say an employee of the school witnessed him checking car doors while he walked around the lot with a woman.

Shannon Flanagan, 20, of North Caldwell, was also arrested and charged with conspiracy.

Rivera faces eight counts of theft to motor vehicles for one incident which allegedly took place Saturday as well as seven others reported at the school over the past month. He was also charged with possession of marijuana and drug paraphernalia. 

North Caldwell Chief Mark Deuer said he did not know the total value of the proceeds, which included designer purses and gift cards. There was no forced entry to the cars, the chief added.

Rivera was transported to the Essex County Jail in Newark, processed and released on $25,000 bail.

Flanagan was released after making bail which was set at $2,500.

Rivera's car was impounded and police are waiting for a search warrant to further their investigation.