By Michelle Durham

PHILADELPHIA, Pa. (CBS) — As funeral preparations continue for slain Plymouth Township police officer Bradley Fox (see related story), attention returns to a Philadelphia cold case: the 1999 disappearance of Maria Procopio.

The connection between the two?  Procopio’s former boyfriend was Andrew Thomas, the man whom Montgomery County officials say shot Fox in the head last week before killing himself (see related story).

Radnor Township police superintendent Bill Colarulo remembers Thomas well.  Colarulo was a captain of South Detectives in Philadelphia and picked up Thomas up for questioning in connection with the Procopio case.

“He reluctantly agreed to take us to his apartment,” Colarulo recalls.  “And as soon as we pulled up, he got out of the car and ran. We had to tackle him.  And I had to make the decision, do we get a warrant, or do we have enough to justify making an immediate entry?  Because it was my belief that Miss Procopio could have been inside.”

She was not, but Colarulo says inside the apartment they found ammunition, night vision equipment, and fake IDs.

Colarulo says Thomas was apparently no newcomer to crime.

“He was handcuffed to bench in South Detectives and he had something in his mouth. And we found out he had a handcuff key hidden under his tongue.”

That prompted Colarulo to send Thomas to the hospital for a full body cavity search.

As for whether clues in connection with Fox’s death will help solve the Procopio case, Colarulo says it’s probably too late:

“The disappearance of Maria Procopio, in my opinion, will always be a mystery.”