VAPORIZERS AND IT CAN ONLY BE

OBTAINED AFTER A DOCTOR GIVES

A CERTIFICATION TO THE

PATIENT.

TONIGHT PRESIDENT OBAMA

WILL HOLD A TOWN HALL MEETING

TO DISCUSS GUN VIOLENCE IN THE

UNITED STATES.

CLOSER TO HOME, WE ARE GETTING

A RARE LOOK AT THE NYPD'S

EXTRAORDINARY EFFORTS TO GET

GUNS OFF CITY STREETS.

CBS 2'S ALICE GAINER WITH A

LOOK INSIDE AT HOW THEY WILL

INVESTIGATE.

DETECTIVE IS FIRING INTO

THE BULLET RECOVERY TANK.

Reporter: WELCOME TO WHAT'S

KNOWN AS THE TANK ROOM INSIDE

THE NYPD'S FORENSICS LAB IN

QUEENS.

THIS TANK IS SO THAT WE CAN

DISCHARGE A WEAPON AND GET

THAT BULLET OUT OF THE GUN FOR

EVIDENCE.

IT WILL TRAVEL THROUGH THE

WATER AND EVENTUALLY DROP TO

THE BOTTOM OF THE TANK.

Reporter: THEN RECOVERED

AND IT IS COMPARED WITH THE

MARKINGS ON THE BULLET TO A

DATABASE OF CRIMES AND TEST

FOR FINGERPRINTS.

IT'S ALL PART OF A LENGTHY

PROCESS TO RID THE CITY OF

ILLEGAL GUNS THAT STARTS ON

THE STREETS WITH NIGHTLY

PATROLS.

OUR MAIN GOAL EVERY DAY IS

TO MAKE A GUN ARREST.

Reporter: THE NYPD'S ELITE

ANTICRIME TEAM ALLOWS A CAMERA

TO INTERVIEW THEM IN THEIR

UNDERCOVER CAR.

AT THE START OF YOUR DAY,

YOU DON'T KNOW WHAT YOU'RE

GOING TO ENCOUNTER THAT NIGHT.

Reporter: THE OFFICERS SAY

THEY HAVE SEEN AND CONFISCATED

IT ALL.

WE HAVE RECOVERED FROM TWO-

SHOT DERRINGERS TO ALL

DIFFERENT TYPES OF REVOLVERS,

SEMI-AUTOMATIC FIREARMS HELD

TOGETHER BY DUCT TAPE.

Reporter: THEN IT'S BACK TO

THE FORENSICS LAB WHERE AS

MANY AS 9,000 FIREARMS WERE

EXAMINED LAST YEAR ALONE.

IT HAS THAT ANTIQUE LOOK TO

IT.

Reporter: LEADING TO MORE

THAN 3,000 ARRESTS.

IT'S A NARROW DICHOTOMY.

WE WANT TO DO A GOOD JOB AND

MAKE GUN ARRESTS AND WE WANT

TO GO HOME SAFELY IN ONE

PIECE.

Reporter: WHICH THE

OFFICERS ADMIT IS NOT ALWAYS

EASY.

ALICE GAINER, CBS 2 NEWS.