Criminal charges facing a prominent Quincy developer whose speedboat killed a close friend in Edgartown harbor on the Fourth of July appear to be losing steam.

Two weeks ago, William O'Connell won back his driver's license halfway through a 120-day suspension for refusing to take a breathalyzer test after police arrested him on the docks at Oak Bluffs harbor. Mr. O'Connell was piloting the 47-foot cigarette boat when its propellers struck 62-year-old William Sanderson.

It was the second break for Mr. O'Connell since the summer holiday tragedy. Police had initially charged him with fleeing the scene of a fatal accident, but prosecutors wouldn't even pursue that complaint.

"I'm not satisfied there's enough evidence on leaving the scene," Cape and Islands first assistant district attorney Michael O'Keefe told the Gazette in July.

Now, Mr. O'Connell appears poised to beat the charge that he was drunk when he pulled his boat, Thunder Enlightening, up to the Chappy Point Beach. Mr. O'Connell's defense attorney Charles Morano convinced Edgartown district court judge Brian Rowe to overturn the license suspension, arguing that Mr. O'Connell had already submitted to a portable breathalyzer which registered his blood-alcohol level at .06, under the legal limit of .08.

Yesterday, Mr. O'Keefe, who is running in the November election for the district attorney's seat, told the Gazette that Judge Rowe's action sends a signal.

"If someone blows a zero-six, no matter what the machine is, it's some indication to the judge that this is not a significant part of the case," he said.

Police had maintained they had other evidence that Mr. O'Connell was drunk, but Mr. O'Keefe would not say whether prosecutors would drop the charge of operating under the influence.

The three charges facing Mr. O'Connell are all misdemeanors. The first two counts of negligent operation of a motor boat resulting in death and operating a motor boat while under the influence of alcohol each carry a maximum jail sentence of two and a half years. The third charge of operating a motor boat within 150 feet of a swimming beach is punishable by a six-month jail term.

Back in July, Mr. O'Connell had appealed to the Registry of Motor Vehicles to have his license reinstated, but the registry denied the appeal.

According to official reports of the July 4 fatality, Mr. O'Connell had pulled his boat onto the beach on Chappaquiddick to let his son and two grandchildren go ashore.

Mr. Sanderson had helped them off the boat and then walked back into the shallow water along the starboard side of Mr. O'Connell's 500-horsepower boat.

Officials speculated that Mr. Sanderson was trying to reach a swimming platform at the rear of the boat, but the propeller had been left running in reverse gear, sucking the victim into the blades and then underneath the boat.