BROOKLYN - The trial of a 14-year-old accused of fatally shooting a Brownsville father on his way home from work got underway Monday afternoon.

Prosecutors say 39-year-old Angel Rojas was shot in the head by Kahton Anderson, who was aiming at a rival gang member while aboard the B15 on March 20, 2014.

Prosecutors say Anderson was part of the “Stack Money Goons,” a gang out of the Sumner Houses in Bedford-Stuyvesant.

They then claim Anderson ran off the bus and continued shooting down Marcus Garvey Boulevard until he ran out of bullets.

Prosecutors even said witnesses claim they saw him smiling.

The defense disputed all of the claims, saying Anderson felt threatened by the rival gang members and was running for his life, not smiling.

Defense attorneys said it wasn't a case of depraved indifference but rather self-defense with tragic consequences.  

In court, Rojas' widow wiped away tears as the opening statements were delivered and was emotional taking the stand as the first witness.

The bus driver of the B15 took the stand as well, describing how she picked up the various passengers and let Anderson off the bus when she realized he could be a threat.

Surveillance video from the bus was also shown to the jurors.

The trial will continue on Tuesday.