The Honolulu Police Department tried to cover up evidence that one of its officers was involved in an improper high-speed chase of a pickup truck that crashed into a group of pedestrians waiting to cross Kamakee Street along Ala Moana Boulevard in January, according to a lawsuit filed Monday in state court.

Accused truck driver Alins O. Sumang, 27, is charged with one count of manslaughter for each of three pedestrians who died in the Jan. 28 crash, one count of assault for each of three other pedestrians who were injured and another assault charge for the injuries suffered by the driver of a vehicle waiting at the traffic light.

Sumang is scheduled to stand trial in February in state court. He remains in custody in lieu of $1 million bail.

HPD officer Sheldon Watts testified in a court hearing one week after the crash that he looked for and followed, not pursued, Sumang on Keeaumoku, Rycroft, Pensacola, Kona and Piikoi streets. He said he was stuck in traffic about a third of a mile behind on Ala Moana Boulevard when Sumang’s truck turned abruptly onto Kamakee Street.

According to the lawsuit, the HPD closing report of the incident omits a statement from a witness who told officers at the scene, “The cop was chasing um from like um Pensacola,” and a statement from another witness who said the pickup truck was, “followed closely by an HPD SUV.”

Other evidence, including video from a city bus and a condominium tower on Ala Moana Boulevard, shows that Watts’ subsidized vehicle was much closer to the pickup truck than one-third of a mile and that its blue lights were not flashing or its siren blaring, the lawsuit says.

HPD’s motor vehicle pursuits policy requires officers involved in pursuits to continuously use their vehicles’ flashing blue lights and sirens. The policy says a pursuit should stop when the risk it creates is unreasonable given the need to apprehend the suspect and the need to avoid harm to persons and property.

Reino Ikeda, 47, of Japan; William Travis Lau, 39, of Honolulu; and Casimir Pokornoy, 26, of Pennsylvania died in the crash.

Pokornoy’s mother, Gail Garin, and two pedestrians who survived the crash, Lianna McCurdy and Daniel Verderame, are suing Sumang, Watts and the city.

An HPD spokeswoman said the department cannot comment on pending litigation.

Verderame was Pokornoy’s best friend. He and McCurdy were hosting Pokornoy and his girlfriend, who also survived the crash, on their visit to Hawaii.