For purposes of this chapter a person is guilty of conspiracy when he, intending that conduct constituting an offense under these ordinances whether he specifically intends to violate the ordinances or not, agrees with one or more persons to engage in or cause the performance of such conduct and any one of them commits an overt act in pursuance of the conspiracy, except where the offense is arson, or burglary, the overt act is not required for the commission of the conspiracy. (Code 1975 § 13-421)