suspect

The suspect died at the scene after exchanging gunfire with police.

They say the suspect then entered an elevator, went up to the ninth floor and that's where he shot two other people who later died.

AMNA NAWAZ: So it's been almost 30 years since Tupac was killed, for decades, no suspects, no convictions.

If a positive reaction for blood is confirmed, however, DNA tests can be especially useful for identifying and eliminating potential suspects.

GEOFF BENNETT: It is the second time this week that New York police have taken deadly action towards a knife-wielding suspect.