Police said the alleged prostitute advertised herself as "Island Hottie" and offered sex for $250 per hour.
The criminal complaint said the sting happened on Sept. 9 when Chief Andrew Lisiecki set up a date at a Green Tree hotel.
According to police paperwork, Lisiecki paid Akudo Duro, of Fort Lauderdale, Fla., with official funds, then got naked and laid on the bed.
"It's very rare to see in an affidavit of probable cause, actual touching goes on," said attorney Blaine Jones.
The report said the chief allowed the woman to begin performing a sex act on him. At some point after that, he informed her that she was under arrest.
Jones, who has represented accused prostitutes in past, said the chief's actions are questionable.
"The money is on the table, should have been case closed," said Jones.
Lisieki said the exchange of money was not enough to warrant an arrest.
"Once she pulled out condoms, everything else was implied. Once agreement was made, an arrest was affected," said Lisieki.
Lisieki also told Channel 11 News that Pittsburgh police are doing such a good job of cracking down on prostitution that more prostitutes are showing up in suburbs.