A recent police chase of four gang members through residential streets and yards off Freeport Street and Morrissey Boulevard could soon be factored into a challenge of a ballot law that has reduced penalties for possessing an ounce or less of marijuana.

The Saturday night chase ended with police shooting one of four men after he allegedly pointed an assault rifle at officers. The man shot by police was Marvin Veiga, 21, of Dorchester, who is being held on $500,000 bail.

He is the same man law enforcement officials say was out on bail and in violation of a court order barring him from Dorchester, stemming from a Jan. 23 incident where he was charged with possession of a 9mm handgun. In that incident at the Freeport exit off Route 93, according to Suffolk County District Attorney Dan Conley’s office, a State Police trooper had stopped a car in which Veiga was a passenger for excessive window tinting. The trooper smelled marijuana and searched the vehicle, allegedly finding a loaded handgun in a backpack next to where Veiga was sitting.

But Veiga’s attorney filed a motion to suppress the gun, which a judge allowed in ruling that because of the marijuana law, which reduced the penalty for possessing an ounce or less of marijuana from an arrestable offense to a $100 civil fine, the officer did not have probable cause to believe there was more than an ounce of marijuana in the vehicle. A separate judge then lowered Veiga’s $30,000 bail to $5,000, over the objection of prosecutors, but granted the request to bar him from Dorchester.

The suppression of evidence ruling has been appealed to the state Appeals Court. Voters approved the marijuana law on the 2008 ballot, despite significant opposition from law enforcement officials.

Conley said this week that he plans to appeal the case “all the way” to the Supreme Judicial Court. Law enforcement officials view the Veiga case as a better test case against the marijuana law than a similar case currently wending its way through the judicial system.

Police say that the four gang members, including Veiga, involved in the Saturday night chase were on their way to murder somebody with some high-powered weaponry when members of the Youth Violence Strike Force tried to pull them over at Adams and East streets around 11 p.m. Instead, the driver sped off and tried to get onto I-93 at Freeport Street, only he failed to make the turn onto the ramp and crashed into a guard rail, police say. Three of the four then got out of the car and ran through nearby Everdean and Mill streets, police say.

“During the pursuit of one of the suspects, officers observed him to be in possession of an assault rifle and commanded him to drop it numerous times” police said in their release. “The suspect ignored officers’ commands and instead turned and pointed the rifle in the direction of the officers. As a result of the suspect’s actions, one officer discharged his firearm, striking the suspect in the leg. The suspect was transported to Boston Medical Center with a non-life threatening injury.”

Morrissey Boulevard by Freeport Street was briefly shut down as police hunted two of the suspects. Police set up a command center on Freeport Street to process evidence and witnesses; homicide detectives were on the scene, along with officers from across the city. One officer was hurt during the pursuit.

Police say they recovered a loaded military style assault rifle from the scene as well as a .40 caliber handgun and approximately forty rounds of ammunition and several face masks.

“This is a clear case of a group of gang members who were on a mission to carry out a senseless act of violence,” Police Commissioner Edward Davis said in a statement. “The intervention by our courageous officers undoubtedly thwarted a homicide. This level of gun violence is unacceptable and illegal guns must be a priority at all levels of government.”

Osvaldir Mendes, 23, of Dorchester was charged with refusal to submit/stop for officers, unlawful possession of a firearm, possession of a machine gun, possession of a firearm with an altered serial number, unlawful possession of ammunition, resisting arrest, reckless operation of a motor vehicle, being and armed career criminal, and a host of other motor vehicle violations. Takari Elliott, 18, of Dorchester, and Daronde Bethea, 18, of Milton, were charged with unlawful possession of a firearm, possession of a machine gun, possession of a firearm with an altered serial number, unlawful possession of ammunition, possession of a large capacity feeding device, possession of loaded firearm, and resisting arrest.

According to Conley’s office, Mendes was held on $150,000 and had his open bail on a separate drug charge revoked, and Bethea and Elliott were both held on $100,000.