An expert witness called by city attorneys testified Wednesday that a Taser likely didn’t work on Sheldon Haleck, who was pepper sprayed by police officers multiple times and shot with a Taser stun gun twice before becoming unresponsive and later dying.

The testimony in a trial in which three Honolulu police officers are being sued for allegedly using excessive force is part of the city’s effort to convince jurors that the actions of the police officers that night four years ago were not only reasonable, but likely didn’t cause Haleck’s death.

Attorneys for Haleck’s family sought to undermine the witness’s testimony, pointing out that he serves on the board of Axon Enterprise, formerly known as Taser International, which manufactures the devices and has been well compensated by the company that he also owns stock in.

Haleck’s family is suing officers Christopher Chung, Samantha Critchlow and Stephen Kardash in a civil case. The city is expected to cover any damages if the court ultimately rules in favor of the plaintiffs, according to the police union.

The city’s expert witness, Mark Kroll, explained to the jury that when a Taser is deployed it shoots two darts that ideally lodge in a person’s skin causing their muscles to lock up and forcing them to fall to the ground. But Kroll said that he didn’t think that happened to Haleck based on police videos and reports that he reviewed. Kroll is an expert in biomedical electricity.

Two videos, which were publicly released several months after Haleck’s death in 2015, and replayed by the media, show officers yelling at Haleck to get on the sidewalk. The footage was taken from the Taser itself, which records when the device is fired. Loud crackling sounds can be heard in both videos as the Taser is deployed. Kroll said that the loud noise means there isn’t a connection — the two probes aren’t connecting with Haleck’s skin to deliver a pulsed electrical current that would immobilize him for several seconds.

Chung initially shot at Haleck’s chest area, according to the video footage. Kroll said that while the two probes didn’t connect to incapacitate him, Haleck may have felt a half second to one second of electrical current. Kroll notes that in the video Haleck seems to briefly bend over after the Taser is fired.

Kroll said that he also didn’t think the Taser worked the second time that it was fired either — this time aimed at Haleck’s back.

“Had there been a connection, he would have fallen over like a domino,” said Kroll.

Kroll said that the Taser did not cause Haleck to go into cardiac arrest, nor did it cause his death.

Earlier in the trial, Irminne Van Dyken, the doctor who treated Haleck that night, testified that she removed two Taser darts from Haleck’s back. Kroll said he was not aware of that.

Attorney Gina Szeto-Wong, who is representing the Haleck family along with Eric Seitz and Della Belatti, sought to cast doubt on the impartiality of Kroll during cross-examination. Kroll, she pointed out, was paid $350,000 by Axon last year, owns $1 million in company stock and sold $375,000 in company stock last year. Kroll is also chairman of Axon’s litigation committee.

Szeto-Wong also confirmed in questioning Kroll that many of the citations in his work are to studies that were funded by Taser and authored by himself.

Taser International has spent millions on studies and forming close ties with police and medical examiners, a multipart investigation by Reuters in 2017 found. When someone dies after an incident involving a Taser, the company has quickly tried to guide investigators, according to the report.

Szeto-Wong also questioned Kroll about a warning on Tasers that the chest area be avoided because it can cause cardiac arrest.

Kroll said that was only a theoretical risk and that there aren’t any cases in which that has happened. He said that those recommendations were written by attorneys, not scientists and doctors.