A 13-year-old boy fatally shot a man on an RTD bus in Denver seconds after the man approached him in the back of the bus, according to an arrest affidavit released Thursday.

Richard Sanchez, 60, was shot multiple times after a confrontation with three juveniles on a bus near South Federal Boulevard and West Mississippi Avenue on the evening of Jan. 27.

Police initially reported the boy shot Sanchez during a “verbal exchange” about Sanchez’s leg blocking the aisle.

The heavily redacted affidavit gives further details about the encounter, which lasted less than two minutes from when the juveniles boarded the bus, according to a surveillance video transcript.

The three juveniles boarded the bus at 6:37 p.m. and walked down the aisle past Sanchez, whose leg was extended into the aisle. They stepped or jumped over his leg, according to the affidavit.

Witnesses told police “words were exchanged with the juvenile” while the group attempted to walk past Sanchez.

Just over a minute later, Sanchez walked toward the back of the bus and stepped up onto the raised platform, facing the boy. Witnesses told police there was a “verbal altercation” at that time.

Four seconds later, the boy reached into his sweatshirt, drew a handgun, aimed it at Sanchez and fired seven times, according to the affidavit.

Sanchez collapsed backward on the floor near the rear door, and the three juveniles exited the bus.

One of the other juveniles appeared to point a handgun at Sanchez and step over him as they exited, and the 13-year-old also stepped over Sanchez and out the back door, the affidavit states.

Sanchez was pronounced dead at Denver Health later that night.

The 13-year-old was arrested Feb. 1 and is facing 14 charges including first-degree murder, according to the Denver District Attorney’s Office.

The boy is also charged with assault, endangering a public transport crew, and possessing a gun as a juvenile, according to the Associated Press.

Prosecutors have not determined whether they will seek to move the case to adult court, the district attorney’s office said this week.

The boy was identified by police through body-worn camera footage from previous encounters with officers. School administrators also identified the boy using images from the bus surveillance video, according to the affidavit.

One person interviewed by police reported that one of the juveniles told them they had hurt someone and was sorry, but the juvenile would not say if they were involved in the bus shooting, according to the affidavit.

Because of redactions to the affidavit, it is not clear if the person interviewed by police was speaking about the 13-year-old suspect.

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