by KYW's Tony Hanson

A federal jury in Philadelphia has returned a mixed verdict in the case against Milton Street, brother of the former mayor.

The jury found Street not guilty of some of the most serious fraud charges against him by the federal government -- charges brought in connection with Street's contracts for work at Philadelphia International Airport.

Street (in file photo above) was found guilty of failing to file tax returns for three years -- 2002, 2003 and 2004. He testified during trial he believes that income tax is unconstitutional (see previous story), but the jury didn't buy that explanation. 

And the jury could not reach a verdict on whether Street, a former Pennsylvania state senator, had assisted in the filing of false tax returns -- under-reporting his income for the tax years 2000 and 2001.

A co-defendant also charged with fraud and conspiracy in connection with the airport contracts was acquitted of all charges.

A relieved Milton Street says it was a long, exhausting, and humbling experience:

"No corruption, no fraud. No corruption, No fraud. Failure to file is something that I was found guity of, but as long as there was no corruption and no fraud and no wrongdoing, then I am happy."

Outside the courtroom, federal prosecutor Jennifer Williams concentrated on the convictions her team obtained. She said that Street now faces the possibility of 2-3 years in prison when he is sentenced in May. She says the government has not decided whether to retry him on those charges for which the jury could not reach a unanimous verdict.