NEW HAVEN - Alex Garcia, 37, of Danbury, pleaded guilty on June 15 before US District Judge Jeffrey Alker Meyer to a federal firearms offense related to the January 2000 murder of Mark Rebong, 28, of Newtown, according to a statement from US Attorney Deirdre M. Daly.

According to court documents and statements made in court, on January 17, 2000, at approximately 11 pm, Mr Rebong was discovered in the driver's seat of an idling vehicle in the vicinity of Exit 2 off Interstate 84 in Danbury. Mr Rebong had been shot once in the head while on his way to work at what was then the Danbury Hilton. Mr Rebong died as a result of his injuries.

The Rebong murder was long considered a case in which the investigative leads had gone cold. But in late 2015, Garcia was arrested in connection with the death. Garcia initially pleaded not guilty.

The police investigation revealed that Garcia was a member of the Latin Kings crime gang. In late December 1999, there was ongoing dispute in Danbury between the Latin Kings and another criminal gang, The Crips. On December 28, 1999, that dispute escalated as a result of the shooting of a high-ranking member of the Crips.

On January 17, 2000, Garcia was a passenger in a vehicle traveling on westbound I-84. The driver of the vehicle, a high-ranking member of the Latin Kings, saw Mr Rebong driving near them on the highway and told Garcia to shoot at Rebong's vehicle. Garcia then used an assault rifle to fire two rounds at the vehicle. As a result, Mark Rebong was killed, according to Ms Daly.

Mark Rebong was neither a member of a gang nor engaged in any criminal activity.

"This defendant brutally and senselessly murdered Mark Rebong mistaking him for someone else," Ms Daly said.

"Mark was a complete innocent gunned down while driving to work, which makes his death all the more tragic… We hope that this conviction brings his family some measure of solace. The investigation of this matter continues," Ms Daly said.

In court on June 15, Garcia pleaded guilty to one count of use of a firearm during and in relation to a crime of violence. Sentencing is slated for September 20, at which time Garcia faces a maximum life prison term. In a binding plea agreement, a prison sentence of 30 years was determined to be an appropriate disposition, according to Ms Daly.

Garcia is in state custody and is serving an unrelated 40-year sentence.