"They not only betrayed my trust, but betrayed the trust of everyone who works here and the citizens," Clarke said. "These vehicles are paid for by taxpayers."
The pool cars, which are kept on a municipal lot near City Hall, are available to Council members and designated staffers, all of whom must have their licenses checked monthly.
Anyone who takes a car must sign a log and put in writing where he or she is taking the car and when he or she will return it, Clarke said. Staffers also must have authorization from a Council member.
Including the 17 Council members, 57 people are cleared to drive one of the pool cars. Jones, whose license was suspended, was not one of those people.
Williams was allowed to drive a pool car, as long as he was authorized. He did not have that authorization Friday.
Clarke said he thought the policy governing the pool cars was sound.
"I'm told I'm not supposed to use the term stealing the key, so I won't use it officially," he said. "But if somebody decides to take the key, there's not much you can do about that."
Clarke said he didn't know of any other times when a Council employee might have taken a car without authorization - and he didn't know how he could investigate if it had happened in the past.
He also said he didn't know if Williams and Jones had been together Friday night before their arrests.
"The keys were where they were for the past 20 years," he said. "They were in a drawer. They were accessible if people knew where the keys were."
When the receptionist who normally was in charge of the keys wasn't working, Williams typically was put in charge of them. That was the case on Friday.
Williams had worked as a sergeant-at-arms since 2004. Jones had worked in the Council president's office since 1998.
Sergeant-at-arms is a patronage job whose most public function is maintaining order at Council meetings. City Hall sources said Williams is the nephew of Sheriff Jewell Williams.
Through a spokesman, the sheriff said Monday that he wouldn't comment on any aspect of the arrests.
Rodney Williams, 41, and Jones, 50, both were charged with DUI and released. Jones also faces a charge of driving on a suspended license. Both have court hearings scheduled for Oct. 11.
Contact staff writer Troy Graham at 215-854-2730 or firstname.lastname@example.org, or follow on Twitter @troyjgraham.