According to The Denver Post, Henderson, 48, was shot 10 times by two separate weapons Oct. 12, 2016. Three of the wounds were fatal, the newspaper reported.
Terance Black, 26, and his mother, Tina Black, 51, were sentenced Thursday to life without the chance of parole for Henderson's murder, The Denver Post reported. They were convicted of the crime Feb. 15 following a four-week trial.
In addressing the court during the sentencing, Tina Black said she does not condone “black-on-black crime” and denied her family’s involvement in Henderson’s killing.
"Where's the justice?" Tina Black said, according to The Denver Post. "I lose my son and you lose your son."
A third defendant in the murder case is awaiting trial.
George Brauchler, district attorney for Arapahoe County, described the convictions and life sentences as “bittersweet.”
"This is the nightmare scenario, where sensitive information is accidentally sent to absolutely the wrong people," Brauchler told The Washington Post. "You had a good man who was trying to do the right thing."
The victim’s sister, Karen Henderson-Atkins, said after the Blacks’ sentencing that she had never seen her brother so scared in his life. He was trying to come up with the cash to flee to Florida when he was killed.
"He didn't have the proper protection," Henderson-Atkins told The Denver Post.
ABC7 in Denver reported that Henderson was hired to work on the car, which belonged to a friend of the Blacks, after Tina Black found him through a Craigslist ad.
He was working on the car outside the Blacks’ hotel room when Terance Black and his accomplices returned from allegedly committing the robbery at the dispensary. Henderson saw them unload more than 440 pounds of stolen marijuana.
Henderson later told investigators he was scared and tried to avoid making eye contact with the group, the news station reported.
His fear was justified -- at one point, Terrance Black pointed a gun at Henderson and another witness and said, 'Y'all mother(expletive) better not say (expletive) or I'll kill both of y'all," affidavits obtained by the news station said.
Henderson was unable to finish fixing the car, because he didn't have the right parts, and Tina Black drove him home, the affidavits said. That was when he spotted the masks and gloves, of which he snuck photos. He also took photos of Tina Black's car and license plate.
A fatal mistake
Brauchler explained to The Washington Post that the fatal mistake in the robbery case was surprisingly simple. The Colorado statewide court software system's default setting was to send criminal complaints and affidavits to all parties in a case, including defendants and witnesses. To keep those documents from certain parties, someone had to "uncheck" a box in the system.
The box in Terance Black's robbery case was left checked and the defendant received unredacted documents that detailed Henderson's cooperation with authorities, the newspaper said.
The documents' release caused fear for other witnesses and a cooperating co-defendant, The Denver Post reported. At least one witness fled the state and others were given added protection.
The Blacks reportedly had gang affiliations, Brauchler told the newspaper.
The murder case against the Blacks was kept under wraps, even through the trial, until the day before sentencing, because of threats against other potential witnesses in the robbery case, the paper said.
The Washington Post reported that court documents indicate the night Henderson was killed, an unnamed woman who knew both Henderson and the Blacks bought crack cocaine from the mother-son duo, who, saying that "snitches get stitches," asked where Henderson was. The woman told them she was on her way to see him.
A group from the hotel where the Blacks were staying followed the woman as she picked up Henderson and drove around with him, smoking crack, the records show. When she dropped him off at the apartment he shared with his mother, gunshots rang out and the woman fled.
Henderson's mother heard his death from inside their apartment, The Washington Post reported.
System changes made
The Denver Post reported that the Henderson case is not the only one in which documents were released to the wrong people. In one robbery case in Arapahoe County, the suspect knew investigators were coming for him because he received the court documents in the mail prior to his arrest.
In a child sex abuse case, two defendants were able to flee the country because the court documents tipped them off, the newspaper reported.
Brauchler told the paper at least 100 Arapahoe County cases were affected by these mistakes.
His office brought the issue to the attention of state officials, who acted immediately to solve the problem. Rob McCallum, a spokesman for the Colorado State Court Administrator's Office, told The Denver Post that officials discovered the same oversight was happening in multiple jurisdictions.
A fix was in place within six weeks, McCallum said.
The spokesman told The Washington Post the system now requires a judge to manually select which parties will receive the court documents.
McCallum said it was likely a judge involved the Blacks' robbery case who failed to uncheck the box that led to Henderson's killing. To his knowledge, no one has been disciplined for the mistake, he told the newspaper.