PLATTSBURGH A joint investigation between the New York State Police Computer Crime Unit and the Plattsburgh Police Departments detective division has resulted in the arrest of a city man. On the morning of Oct. 15, city police detectives and state police investigators executed a search warrant at 24 Broad St., Apt. 2, searching for child pornography. The resident, Joseph M. Shay, 55, was located within the apartment and brought to the Plattsburgh police station for questioning. It is alleged that in July, the defendant, possessed and promoted a sexual performance by a child less than 16 years of age over the Internet. Shay has been charged with one count of promoting a sexual performance by a child, a Class D felony, and one count of possessing a sexual performance by a child, a Class E felony. The defendant was arraigned in Plattsburgh City Court Oct. 15. The investigation is continuing.