TAMPA — Police have made two arrests in connection with the shooting death of 20-year-old Nicholas Mortazavi at a South Tampa McDonald's on July 20, the result of what police said was a drug deal gone bad.

Police arrested Marquez Davon Roberts, 19, Saturday after he turned himself in on charges of first degree felony murder, carrying a concealed firearm and uttering a counterfeit instrument, according to jail records. His arrest came days after 17-year-old Dontae Lamar Hopkins, a standout football player at Hillsborough High School, turned himself in to police on Dec. 6 on a charge of third-degree murder involving possession of a firearm.

Hopkins was released from county jail Dec. 7 on a $100,000 surety bond, jail records show. Roberts was still behind bars Monday afternoon with bail set at $104,000.

In a statement released Monday, Tampa Police spokesman Steve Hegarty said investigators believe Roberts and Hopkins planned to purchase marijuana from Mortazavi the night he was killed.

Roberts and several middle-men had arranged to purchase a quarter pound of marijuana from Mortazavi at about 7:45 p.m. at the McDonald's at 3515 S. Dale Mabry Highway, just south of El Prado Boulevard, Det. Stephanie Puleo wrote in Hopkins' arrest report.

Roberts picked up four passengers, including Hopkins, then drove his Dodge Charger to the restaurant's parking lot alongside Mortazavi's vehicle, where he was waiting with three passengers.

Roberts left his vehicle and sat in the back seat of Mortazavi's car to conduct the drug deal, police said. It wasn't until after Roberts returned to his car with the quarter pound of marijuana that Mortazavi realized he had been paid with counterfeit currency, police said.

As an argument escalated, both Roberts and Mortazavi got out of their cars and stood between the two vehicles. Mortazavi attempted to grab the marijuana away from Roberts, and Roberts then pulled a Glock .40 handgun from his right front-pants pocket, pointing it at the victim, police said.

Hopkins, who had watched the altercation from the back seat of Roberts' vehicle, opened the car door armed with a Springfield .40 caliber handgun when he thought he saw Mortazavi reach into his pants, police said. Five witnesses told police they saw Mortazavi fall to the ground after he was shot once in the chest, but offered conflicting statements on whether Roberts or Hopkins pulled the trigger.

Both Hopkins and Roberts blamed the other for firing the fatal shot.

Investigators believe it was Roberts who ultimately shot Mortazavi, leaving him seriously wounded in the parking lot. First responders transported Mortazavi to Tampa General Hospital, where he was pronounced dead early the next morning.

On Dec. 6, a grand jury indicted both Roberts and Hopkins for their roles in Mortazavi's death.

According to his obituary, Mortazavi was a recent graduate of Plant High School who was attending college in St. Petersburg with plans to attend Santa Fe College in Gainesville. He is survived by his parents, Dr. Ali Mortazavi and Lynn Gutierrez-Mortazavi of Tampa, and his three sisters, Kelly and Caroline Mortazavi of San Francisco and Dr. Elizabeth Mortazavi of Tampa.

This is a developing story. Stay with www.tampabay.com for updates.

Contact Anastasia Dawson at adawson@tampabay.com or (813) 226-3377. Follow @adawsonwrites.