Prosecutors did the right thing Wednesday when they withdrew charges in the drug arrest of a grandmother at her Kepple Road home in Buffalo Township. The case against 64-year-old Candace D. Kelly is unusual on several levels, and it merits more investigation before the proper charges can be filed.

The allegation itself is sensational enough: 64 pounds of high-grade marijuana, two pounds of psychedelic mushrooms, three pounds of hashish and $392,000 were uncovered in Kelly’s mobile home. Narcotics officers who knocked on Kelly’s door say she consented to a search and led them to the suitcases stuffed with freezer-dried pot.

But beyond the drugs and cash, the evidence against Kelly is largely circumstantial, which makes the case, at its current juncture, wildly speculative.

Consider the as-yet unanswered questions:

• Who supplied the marijuana? Trooper Jeff Brautigam, of the state police Western Pennsylvania Drug Interdiction Unit, described it as high-grade and potent, meaning it was cultivated by someone with expertise — someone well established in the illegal drug trade. Such people don’t do business with amateurs.

• How many associates can be identified and brought to justice? Some assumptions can be made about a 64-pound stash of drugs and nearly a half-million dollars inside an unguarded mobile home. One such assumption is that only a few trusted individuals must be working as distributors — they would not conduct street-level transactions so close to their secret piles of drugs and cash and risk becoming public knowledge.

• Who controls the profits? Kelly’s rural mobile home certainly doesn’t reflect a lavish lifestyle normally attributed to drug kingpins.

• How did a drug operation of this magnitude unravel so quickly? Drug agents said the case was opened and shut in three hours. By contrast, some undercover operations go on for months and even years.

In fact, the speed at which the case developed presents much of the prosecution’s challenge. The routine tools used to gather and document evidence in narcotics investigations — undercover purchases, informants and surveillance — did not come into play. That fact alone leaves many shadows of a doubt.

Considering the unanswered questions, state prosecutors were justified when they unexpectedly withdrew the felony drug charge against Kelly, who is innocent until proven guilty and, for that matter, currently walks free, not charged with any crime.

However, there is that problem of 64 pounds of marijuana now in police custody, along with nearly $400,000 in cash, and yet one more unanswered question: who really took the financial hit because of its confiscation?