A 52-year-old man was beaten and stabbed to death after bumping into a teen at a Stamford McDonald's and spilling coffee on him, police said on Monday.

Antonio Muralles, 52, of Stamford, was beaten with a stick and stabbed in the heart in front of the fast-food restaurant at 25 Bedford Street on Wednesday evening, according to police, who called the death a "horrendous crime."

Over the weekend, police arrested James McLamb, 22, of New Haven, and a 15-year-old Stamford boy. Both have been charged with first-degree murder.

The stabbing was Stamford's first homicide of 2015.

According to police, things escalated after Muralles and the teen bumped into each other. Muralles tried to apologize, but the group of three to five people did not want to hear it.

Police said they've been going through surveillance video since the attack. An eyewitness also came forward and provided police information on the vicious attack.

The 15-year-old, who has not been publicly identified, allegedly stabbed Muralles several times in the arms and torso, police said. He had been hiding out in Waterbury and was arrested Monday in Stamford after returning home, police said. He was expected to be arraigned in juvenile court in Bridgeport, but police expect him to soon be charged as an adult.

McLamb, who is accused of assaulting the victim during the stabbing, was arrested over the weekend and is accused of possessing brass knuckles, police said. He's being held on $2 million bond.

The arrest warrant for McLamb has been sealed by the court and officials said he has a history of plea bargains for misdemeanor offenses and has not served prison time.

The attorney who represented him in court said McLamb has applied to review the police incident report or warrant.

Muralles was found last week when EMS crews were responding to another unrelated matter at the corner of Broad and Bedford streets at 8:17 p.m. They noticed a stab wound to the chest while treating him.

Muralles was then transported to Stamford Hospital, where he went through emergency surgery for several hours but died at 1:07 a.m.

The assailants had run off after the attack and police reviewed surveillance from the area.

Anyone with information is asked to call the Stamford Police Detective Bureau at 203-944-4417. All calls will be kept confidential.