Michael Sullivan’s grieving family made a desperate plea Tuesday for anyone with information on how the disabled father of two was murdered to come forward to police.

“This was an evil act. A cruel death,” said Sullivan’s sister Teresa Mummery at a press conference at Hamilton police headquarters Tuesday afternoon.

Sullivan became the city's 10th homicide of the year when he died at Hamilton General Hospital earlier this month. The incident, and the frightening circumstances of a driver hunting down and deliberately hitting a cyclist in the city, remained secret from the public for almost three months.

Michael Sullivan, 51, was killed by a truck driver who chased him through the streets of the east end back in July, police say. (Courtesy Hamilton Police)

Sullivan had a disability, and worked from home building or fixing things for other people, his sister said

"When he worked at home it was always building something for somebody else,” she said. “My brother was in a lot of interactions with a lot of good people. He did computers for underprivileged children, he did bicycles and sent them to countries where they didn’t have them. That’s how he filled his days.”

Investigators from the east end division were originally overseeing the case before the homicide unit took over, and they “made the strategic decision” not to release any information to the public, says Hamilton police Det. Peter Thom.

“The decision early on was to go that route,” Thom said. Though police are asking the public to come forward and help with the case, they will not give a specific suspect description or firm reason as to why they did not disclose the murder until last week, even though it happened back in July.

“I don’t want to provide any other information that the witnesses we’ve spoken to so far have issued to us,” he said. “I don’t want to taint anyone else’s information.”

Police have recovered the black Ford F150 they believe was used to run Sullivan down in the east end. It is now at the Centre for Forensic Sciences being examined for further evidence, Thom says. The registered owner of the truck had sold the vehicle months before the murder happened.

“We’re just in the process of figuring out which hands the truck has passed through since that happened,” he said.

Mummery says she believes the police have handled the case in a way that will help catch the perpetrator, and that coming forward earlier “wouldn’t have made a difference.”

Michael Sullivan's mother Gail was one of the family members present at Tuesday's press conference. (Adam Carter/CBC)

Sullivan was riding on his bike in the area of Barton Street East and Lottridge Street back in July.

“While in the vicinity he had a brief interaction with some individuals and continued about his business,” according to a police statement. “This interaction led to some misinformation being passed to the driver of a black, Ford F150 pickup truck.” Thom again would not specify what that "misinformation" was at Tuesday’s press conference.

Police say the driver of the truck chased Sullivan through city streets and then pursued him into the rear lot of a Barton Street East restaurant supply store. The truck hit Sullivan and he flew off the bike, police say.

The driver of the truck sped off after hitting Sullivan and was last seen travelling eastbound on Barton Street, police say.

Sullivan was a father who was adored by his two children: Nathan, 27 and Tara, 21, Mummery said.

“He was so proud of them,” she said. “Their father was a caring human being who loved life and always tried to help people in need.

“They cannot imagine why someone would hurt their father.”