CENTENNIAL, Colo. -- An unsolved Centennial homicide could be linked to people also arrested for a series of racially motivated beatings in LoDo this summer, a law enforcement source confirmed.

At this time, investigators are not releasing the names of the suspects and no one has been charged.

Andrew Graham, 23, died from a single gunshot to his torso during a mysterious confrontation in his Centennial neighborhood on the morning of Nov. 6, the Arapahoe County coroner said after the shooting.

"We do not talk about cases that are not in our jurisdiction," said Denver police spokesman Lt. Matt Murray told 7NEWS, adding that the department also will not talk about the LoDo attacks because the cases have been turned over the Denver District Attorney's office.

Graham's body was found on a residential lawn less than a mile from his parent's home.

Investigators believe the 23-year-old CU engineering graduate student was walking home after getting off a light rail train when some sort of confrontation occurred. Graham had spent the previous night in Boulder looking to lease a home with friends while attending graduate school.

In November, the Denver district attorney filed charges against several people in connection to a string of violent, racially motivated attacks in Downtown Denver over the previous four months.

There were 26 violent attacks between July 17 and Nov. 17 last year, but police did not publicly acknowledge the crime wave in the popular downtown entertainment district until 7NEWS requested crime records for the area on Sept. 3 -- two months into the attacks.

At the time, police spokesman Sonny Jackson said police did not alert the public of the possible threat earlier because "we have to have a pattern of behavior."

An arrest warrant affidavit, obtained by 7NEWS, described one of the downtown attacks in which the victim said he was assaulted during a robbery attempt after he got off the light rail train.

Read the Denver light rail attack arrest affidavits

In the Denver attack, Daniel Brooks said he was waiting for a downtown light rail train at the 16th and California street station after work Aug. 11, 2009 when he noticed three black males and a female "engaging in horseplay with each other," according to Nov. 19, 2009 arrest affidavits for three suspects.

Brooks told police he remembered the group got on the same northbound train that he did. After Brooks got off at the 30th Avenue and Downing Street station, he caught one of the men trying to pick his back pants pocket.

When Brooks confronted the man, he said he was attacked by a second man from the side and a fight ensued.

Several of the suspects admitted their involvement -- or fingered accomplices -- in the attack, the affidavits said. A transit security camera captured the men punching Brooks and also kicking and "stomping" the victim after he was knocked to the ground.

At least three adult males were charged with aggravated robbery and bias-motivated crimes in the Denver attack, according to court records.