CHICAGO (CBS) — Chicago Police Officer Jason Van Dyke’s partner took the stand in the officer’s murder trial Tuesday. Day two of the trial focused around a squad car that pulled up too late to save Laquan McDonald.

Witnesses testified police calls for a taser were answered just one minute too late. Laquan McDonald was already dead on the street.

Several officers working that night in 2014 testified Tuesday. One of them rushed a taser to the scene.

Dash cam video showed the squad car of Officer David Ivankovich, carrying a taser requested by officers, pulling up to the scene; but it was too late. McDonald, shot 16 times, was already down on the ground.

When prosecutors asked, “When you pulled up, you observed Laquan McDonald on the ground, correct?” Officer David Ivankovich replied, “yes.”

Van Dyke’s attorney stressed the call for assistance showed there was danger.

“A hot call means ‘help get here quick,’ right?” prosecutors asked. “Correct,” Ivankovich replied.

Prosecutors tried to stress that there were no pedestrians and little danger. Van Dyke’s partner, Joseph Walsh, shown leaving court, testified he seemed surprised by the gunshots.

“I believe I flinched and bent at the knees. I didn’t realize it was happening, so it startled me,” said Walsh, who did not want his testimony recorded.

When asked if he felt threatened, Walsh said, “He was a threat, with a knife in his hand, moving.”

As McDonald laid on the ground, video depicted several Chicago Police Officers standing nearby until a Cook County Sheriff’s Officer arrived at the scene.

“I observed the subject gasping for air,” recalled Officer Adam Murphy. “I put on my rubber gloves and attempted to give aid.”

He said he told McDonald help was on the way.

The judge thanked the jurors today for doing a good job and for paying attention. Court resumes Wednesday at 10 a.m.