After the Memorial Drive shooting, questions remain about how the alleged gunman slipped through the cracks

The man accused of opening fire on Memorial Drive and wounding two people pleaded not guilty yesterday to armed assault with intent to murder.

As the case against Tyler Brown moves forward, questions persist. How did a man with a criminal history get a gun? Why was he at a psychiatric hospital just three days before the shooting? And how did he slip through the grip of the parole system?

WBUR’s Eve Zuckoff reports.