When the bus stopped, Bishop and Fournier began to argue, after Fournier allegedly told Bishop to "be nicer to passengers".
But as he prepares to step off the bus a person shoves him from behind.
The elderly man refused medication as authorities arrived to treat him.
The victim, identified as Serge Fournier, fell on his head and died from his injuries on April 23.
Fournier landed face-first on the sidewalk on top of the shopping cart he was carrying. He later died from his injuries. Fournier's family notified police on May 3 that he had passed away, and Bishop was arrested three days later.
According to Bishop's arrest report, witnesses to the March incident said she left the bus with her son and didn't bother to offer Fournier any help.
After the alleged shoving, Bishop reportedly fled the scene.
The Las Vegas Metropolitan Police Department has released CCTV that shows the whole event unfold.
Cadesha Michelle Bishop, 25, was arrested Monday on a murder warrant for the death of 74-year-old Serge Fournier. She has been charged with murder and remains jailed on $100,000 bail pending a preliminary hearing of evidence May 21.
Taylor said, "No matter what his age, she should not have done that". He tells us he will never forget his friend.
"He was an excellent neighbor".
Bishop was previously convicted twice in 2012 and 2013 of domestic violence misdemeanors.