ARAPAHOE COUNTY, Colo. — A mother and son were sentenced to life in prison without parole Thursday afternoon for their role in killing an innocent witness to a pot shop robbery in 2016, according to the 18th Judicial District Attorney's Office.

Terance Black and his mother, Tina Black, were convicted last week of first-degree murder in the killing of David Henderson, the district attorney's office said.

Henderson, 48, was found shot to death in Denver near Havana Street and Alameda Avenue on Oct. 12, 2016. Two months earlier, in August of that year, prosecutors said Henderson was a witness in the robbery investigation of Cure Colorado, located at 6200 E. Yale Ave.

David Henderson
Denver Police

On Sept. 21. 2016, Terance Black was mistakenly mailed the affidavit which named David Henderson as a witness. Prosecutors say they tracked him down and killed him about a month later. 

The Blacks received the affidavit as part of a clerical error judges were unknowingly making in Colorado that 9NEWS first reported on last year, and District Attorney George Brauchler says this illustrates the worst case scenario of that error. 

RELATED: Mistakes by Colorado judges put victims and law enforcement at risk

Family of David Henderson
KUSA

According to a recently unsealed arrest affidavit, Henderson got caught up in the pot shop robbery when he was asked to a repair a car for Tina Black. At the time, he didn't have a car, so Tina Black picked him up and took him to the Timbers Hotel at Interstate 70 and Peoria on the day of the crime. He wasn't able to finish the repair of her car because the mechanic shop was already closed.

After this, the affidavit says that Henderson wanted to go home, but had to wait for a ride from Tina Black. She told Henderson she, along with three other men that Henderson didn't recognize, were leaving but would be back. About two hours later, Henderson told police that Tina Black and the other males returned to the hotel with a duffel bag and a trash can filled with marijuana packages.

Tina Black
Arapahoe County Sheriff's Office
Terance Black
Arapahoe County Sheriff's Office

The affidavit says Tina Black and another man Henderson didn't recognize gave him a ride home. While he was in the backseat, he took photos of ski masks and latex gloves. These photos were found by police after he was found shot to death about two months later. Police also found Henderson's text to Crime Stoppers reporting the crime. 

Someone who interacted with Henderson just two days before his shooting death told police that he was "worried" and was trying to get enough money and go to Florida. That witness said that Henderson believed he was "in the wrong place at the wrong time" when it came to the robbery. 

Terance Black was out on bond for the robbery at the time of the killing and was wearing a GPS monitor as a condition of his bond, according to prosecutors.

KUSA

Their cases have not been made public until now, the DA's office said out of fear for the safety of other witnesses and cooperating defendants in the case.

According to the district attorney's office, the Blacks are gang members and other gang members have shown up at hearings in an effort to intimidate others. Some witnesses even fled the state out of fear for their safety, the DA's office said.

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