Drew Peterson Barrel Helper Revealed

It has been revealed that the person who assisted Drew Peterson with loading a barrel into Peterson's SUV was Thomas Morphey, Drew's step-brother.

Morphey was hospitalized the following day for an alleged suicide attempt. A source said Morphey's wife called police, saying her husband heard of the disappearance, became distraught and feared he might have unwittingly helped dispose of Drew Peterson’s wife’s body.

Prosecutors have not called Morphey to testify before a grand jury examining the 23-year-old woman’s disappearance because he has “memory lapses” regarding the barrel.

One would think that this would enough to make an arrest. Why not just ask Drew Peterson where he put the barrel? Is there more to this story than what is being discussed?