Among the considerations - did Neely pose a threat to the safety of other passengers, and did Penny use excessive force when he held Neely in that chokehold, reportedly for about 15 minutes?
The story sparked protests this weekend that made their way down into the Lexington Avenue/63rd Street Station and onto the tracks, forcing trains to stop.
The NYPD is now looking for six people involved in that protest.
RELATED| Jordan Neely's family calls chokehold death on subway an 'injustice'
Protesters take to the subway following Jordan Neely death
As demonstrators cried out, friends remembered a street performer who impersonated Michael Jackson.
However, police records point to a man becoming increasingly violent -- Neely was arrested more than 40 times for multiple assaults, an attempted child abduction, drugs and indecent exposure.
Detectives are also trying to determine if he tried to shove a passenger onto the tracks the day before Neely's own death. There was currently an arrest warrant for Neely in the violent attack of an older woman.
Friends say Neely desperately needed psychiatric help.
"Very concerned for him the last time I saw him. He said 'I'm going to get it together, trust me,'" said Moses Harper.
RELATED| Jordan Neely's family calls chokehold death on subway an 'injustice'
Jordan Neely's family calls chokehold death on subway an 'injustice'
----------
* Get Eyewitness News Delivered
* More Manhattan news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube