Hammond police said they were pursuing a stolen U-Haul truck when it crashed into the Little Calumet River in Chicago in February.
The driver of the truck, 34-year-old Larry Perry, died.
A large group of Perry's relatives and attorneys gathered to hold a news conference Friday morning outside Chicago City Hall, in which they spoke about their wrongful death lawsuit. They demanded police to release information about their investigation, bodycam and dashcam video of the incident, as well as radio transmissions.
Attorneys for the Perry family filed a wrongful death lawsuit Friday morning. They said body camera video and other information would go a long way to prove or disprove the allegations in the lawsuit.
"All we're asking is how did a traffic violation wind up with my brother dead in the river," Perry's sister, Trisha Witherspoon, said. "That's all we want to know."
The family described Perry as a father of four.
"We have no reason, no information on how this happened. It's been two months," attorney Cierra N. Norris said.
Attorneys said the pursuit began after police stopped the U-Haul truck at a gas station on Feb. 21. They have said they suspected it was stolen. The pursuit lasted approximately eight minutes.
SEE MORE: Driver dies after stolen U-Haul truck crashes into Little Calumet River after police pursuit
Officers responded to the area of 136th Street and Sheffield Avenue in Hammond and attempted to curb the U-Haul truck. They began to pursue the truck after it failed to comply and fled the scene, police said.
The U-Haul truck led police to 130th Street and Indiana Avenue in Chicago, where it went over the edge and through a guardrail, ending up in the Little Calumet River, police said.
The driver attempted to swim away, and police officers entered to attempt to rescue the driver, but he went under, police said.
Chicago Fire Department divers responded to the scene and recovered his body.
Police previously said there was a female passenger in the U-Haul truck at the beginning of the pursuit, but she jumped from the vehicle during the pursuit. She was being questioned by police, and had active warrants for her arrest for cocaine possession.
It's not clear why the U-Haul truck was stolen, or if there was anything inside.
Attorneys for the family said they believe police could have violated their own policies by continuing the pursuit.
"There's been no evidence of a felony where it appears someone's life was in jeopardy that the chase had to continue," attorney Greg Kulis said.
Hammond police disagree, issuing a statement in response, saying, "The Department's review of the pursuit of the stolen vehicle that Mr. Perry was driving while fleeing the police confirms that the officers' actions were in accordance with departmental protocols."
Perry's mother, Angela Perry, remains unsatisfied.
"I don't have the cause of death. I don't have nothing," Angela said. "I'm getting the run-around from the coroner."