Suffolk County District Attorney Daniel F. Conley today announced the following preliminary findings of the investigation into the fatal shooting of JAY CARCIERO (D.O.B. 6/22/72) of Reading at 50 Staniford St. on Oct. 27, 2009. These findings reflect evidence developed during an ongoing investigation by the homicide units of the Suffolk DA’s office and Boston Police Department:

“As you know, the homicide units of my office and the Boston Police Department are investigating Tuesday’s fatal shooting at 50 Staniford St. That investigation remains ongoing, with many steps to complete before we make a final ruling on whether criminal charges are warranted. At this stage, however, we’re prepared to state the following:

“At about 2:00 Tuesday afternoon, 37-year-old Jay Carciero of Reading attacked Dr. Astrid Desrosiers with a knife at 50 Staniford St. Carciero was present for a scheduled appointment on a floor with several medical, dental, research, and mental health offices.

“Also present on that floor was a 33-year-old Paul Langone of Reading, who was off-duty but sworn as a special police officer in the City of Boston. Langone heard the doctor’s screams and entered her office to see Carciero atop the doctor and stabbing her. He drew his personal firearm, for which he had a valid Class A license, and instructed Carciero to drop his weapon. Carciero did not follow that instruction and Langone discharged his firearm multiple times, striking Carciero twice.

“Both Carciero and Desrosiers were transported to Massachusetts General Hospital. Carciero was pronounced dead of his injuries and Desrosiers was treated for multiple, life-threatening stab wounds. She is currently expected to survive, but her medical condition has prevented us from interviewing her at this point.

“During and after the incident, Boston and State police received multiple 911 calls and responded to the scene. Langone identified himself as the shooter, acknowledged and surrendered his firearm, and submitted to an extensive interview with Boston Police detectives. He was released from custody after that interview and he has not been charged with any offense at this time.

“Because Carciero and Langone both resided in the same town, investigators in Boston and Reading examined potential links between the two men. They could find no connection or relationship between them prior to the events of Oct. 27.

“The Suffolk DA’s office and Boston Police Department investigate all fatal shootings in the City of Boston, whether by a police officer or a civilian. Many are immediately obvious as criminal homicides; shootings such as this one are very rare. At Staniford Street, we had a civilian shooter using a licensed firearm in apparent self-defense and defense of another. He stayed at the scene and readily identified himself to responding Boston and State Police.

“That investigation remains ongoing and active, but the evidence at the scene, the shooter’s statements, and the accounts of multiple witnesses all indicate that Mr. Langone acted lawfully when he discharged his firearm. There is strong evidence that he saved the doctor’s life — and possibly other lives — in doing so.”