Riverhead retires No. 21 baseball jersey of NYPD Det. Brian Simonsen

Who is NYPD Detective Brian Simonsen? - ABC7 New York

Fund the First Det. Brian Simonsen 3rd Annual Motorcycle Memorial Run

Fallen NYPD Det. Brian Simonsen mourned in communities where he grew up and patrolled - Newsday

NYPD detective slain by friendly fire posthumously promoted at his funeral as thousands gather to mourn – New York Daily News

Crowd Gathers For Street Dedication Honoring Fallen NYPD Hero

Thousands mourn NYPD Detective Brian Simonsen at funeral

A timeline of the friendly fire death of NYPD officer Brian Simonsen

The Detective Brian 'Smiles' Simonsen Memorial Foundation Fundraiser Custom Ink Fundraising

Fallen NYPD Det. Brian Simonsen mourned in communities where he grew up and patrolled - Newsday

Riverhead softball team honors family of fallen NYPD Detective Brian Simonsen