CHICAGO (WLS) -- Testimony got underway Monday in a murder trial that rocked Chicago's Chinatown.

A man is accused of killing a grandfather who was out for a walk nearly four years ago.

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Technology played a huge role in the case. Numerous security cameras captured images of the alleged gunman as well as the car he was driving.

Jurors saw some of that video Monday at the Cook County Courthouse.

A large contingent of friends and supporters, many from Chinatown, left the courtroom during a break Monday.

The shooting of a 71-year-old man in the middle of the day across the street from an elementary school angered many in the community.

Woom Sing Tse was taking a walk in the 200-block of West 23rd Street in the heart of Chinatown.

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