Brown testified against Guyger in court just 10 days ago.

Joshua Brown, a key witness in the trial against Amber Guyger for the murder of Botham Jean, was shot and killed in Dallas on Friday night. Jean's attorney, Lee Merritt, confirmed Brown's death in a Facebook post yesterday, noting Brown "worked closely with prosecutors just a week ago to ensure Amber Guyger was properly convicted in the murder trial."

According to CNN, Brown was gunned down in front of the Atera apartments in Dallas, just five miles from where he, Jean and Guyger lived when the initial murder took place. Brown was pronounced dead at Parkland Memorial Hospital, where he was taken after being discovered laying in the parking lot of his apartment complex with multiple gunshot wounds to the head and chest.

READ: A Manipulation Of Black Innocence: Botham Jean and How Black People are Wrong Even When They're Not

The report states witnesses described hearing several gunshots and seeing a silver four-door sedan fleeing the parking lot, but no other details of the suspected shooter have been revealed.

Brown, who lived down the hall from Botham Jean at the time of his murder, delivered an emotional testimony in court 10 days ago. Of the testimony, Merritt underscored Brown's "constant fear that he could be the next victim of gun violence, either state-sanctioned or otherwise."

Earlier this week, Guyger was sentenced to 10 years in prison for the murder of Botham Jean. She will be eligible for parole after five years.

You can watch Brown's full testimony below.