During the 'explosive device' incident Officer Simmonds received injuries to his left hand, back and ankle. He also suffered blurred vision, the police report says.
However, the shoot-out in Watertown did not begin until 12.45 am, over an hour after Officer Simmonds initially responded, according to the report.
The report does not detail how Officer Simmonds was injured, makes no mention of explosives, and does not explain what occurred during the hour prior to the shoot-out.
It was filed by Sergeant David S Gavin of the Boston Police Department on May 1st 2013, almost two weeks after the shoot-out which also saw MBTA Transit Officer Richard Donahue injured in a friendly fire incident.
After being advised to follow up any further problems with his primary-care doctor, he was relieved of his duty by Sergeant Dennis C. Cogavin of the Boston Police Department. It was four weeks before he returned to active service.
Officer Simmonds responded to the incident accompanied by three colleagues, Officers Jean Gerard Jean-Louis, Gregory McCormick, and Gregory R. Eunis. All were nominated for a 'Top Cop Award' by the National Association of Police Organizations and were recently honoured at a White House ceremony for their efforts in response to the shoot-out.
No autopsy was performed and no cause of death has ever been released.
In a statement released at the time the Boston Police Department wrote:
"Officer Simmonds will be greatly missed by his friends, colleagues and all members of the Department."