ABC News March 15, 2018

Man arrested in connection to string of 2015 shootings in Colorado

WATCH: Colorado man's arrest could be linked to 2015 shootings

After a nearly three year investigation, authorities in Colorado have linked a suspect to a murder and attempted murder that was reportedly in connection with a string of shootings that occurred in 2015.

Christopher David Parker, 35, of Loveland, Colorado, was arrested on March 13 for the murder of William Connole, 65, and the attempted murder of a male motorcyclist that was shot 15 minutes prior to Connole’s murder.

Connole was shot and killed while walking down the street in Loveland, but the motorcyclist wasn't injured.

“He was just a guy walking down the street,” said Mary Connole, William’s sister. “He was a father, a grandfather. He was like your brother.”

The shootings, which were described by authorities as random acts by a serial shooter, even targeted an unoccupied school and a medical building.

Larimer County Sheriff's Office
Christopher David Parker is seen here in this undated file photo.

The Northern Colorado Shooting Task Force (NCSTF), which was formed to investigate these incidents, connected the two shootings Parker was charged with using forensic evidence. In the early stages of the investigation, NCSTF said they believed all six shootings were linked. However, so far the charges and arrest of Parker have not been linked to the other four shootings, which resulted in another death and one woman surviving a shot in the neck while driving her car on Interstate 25.

The death of John Jacoby, who was shot and killed in April 2015 while riding his bicycle in Windsor is one of the other unsolved cases. At this point, officials say they have no evidence linking that shooting to Parker.

Capt. Bob Coleman of the Larimer County Sheriff’s Office, who is also the Commander of NCSTF, said they have received over 5,000 different tips from the public, cleared 12 suspects, and tracked over 12,000 different pickup trucks since the investigation began. Coleman added that the task force, which includes the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) and FBI, had followed up on leads extending into Wyoming and Nebraska.

“This required an immense amount of commitment and tenacity,” Coleman said. “The public will continue to have a vital role. Despite thousands of hours, we are not finished. We still need your help.”

Despite feeling some relief at the possibility of seeing justice served for her brother, Mary encouraged the public to keep helping and support the families of other victims.

“We need to let the system continue to do its job,” Connole said. “Keep in mind the Jacobys and other victims including [Parker’s] mother.”

The NCSTF has set up a tip phone number and email for the public to use: 970-498-5595 or taskforce@larimer.org.