Attempts by St. Paul police to solve the fatal shootings of three people within a five-day span on the city's East Side received a major boost this week with the arrest of five suspects.

Over the course of two days, police arrested a man and a woman in connection with the killing of a young mother in the Railroad Island area Sunday, and also arrested three men — one of whom was later charged with murder — believed to have been involved in the drive-by shooting of a gang leader on the Earl Street Bridge three nights earlier.

As of Wednesday, police had yet to make an arrest in the shooting death of Synika James, 37, who was shot to death while attending a vigil for a woman shot and killed by an alleged gang member near the same spot on the East Side three years earlier.

"Our investigators are working hard, and they are making positive headway," police spokesman Steve Linders said Wednesday night, adding that more information about the cases should be forthcoming in the next few days.

St. Paul Mayor Chris Coleman and police officials met with more than 100 residents Wednesday night at the East Side precinct headquarters on Payne Avenue to talk about the shootings and reassure them that investigators are working to quickly solve the crimes.

"We can turn this thing around," Matt Toupal, senior commander of Eastern District, told the audience. "We will turn this thing around."

On Tuesday night, police arrested a 42-year-old woman and a 24-year-old man with extensive criminal histories in connection with the death of Sarah Anne Wierstad, 24, who was shot just steps from her house as she was returning home from work. Wierstad, the mother of a 5-year-old girl, worked two jobs and was attending school in hopes of becoming a chef.

According to the Ramsey County jail, police arrested the woman on suspicion of murder. Court records show she pleaded guilty to second-degree murder in 1998 for her part in a drive-by shooting in Anoka County in which she drove her brother past a house as he fired a shotgun, hitting and killing a man as he slept inside. She got out of prison in 2013, according to the Minnesota Department of Corrections, and was on supervised release when arrested this week.

Also arrested Tuesday in connection with Wierstad's death was a 24-year-old man with a criminal history that includes convictions for aggravated robbery and trespassing.

The Star Tribune generally does not name suspects until they are charged.

While police worked to solve Wierstad's killing, authorities Wednesday charged a 24-year-old St. Paul man with murder in connection with the drive-by shooting last Thursday night on the Earl Street Bridge. Two men riding in the car with him that night also were arrested this week.

Dametrius Ratheal Adrian Moore was charged in Ramsey County District Court with second-degree murder in the death of Emmett L. Wilson-Shaw, 24, as Shaw and four friends walked across the bridge, a criminal complaint said.

Moore, the driver of the car from where the shots were fired, also was charged with several counts of drive-by discharge of a firearm and second-degree assault.

According to the criminal complaint:

Wilson-Shaw, identified as a "high-ranking member" of the East Side Boyz gang, and four companions were walking over the bridge about 7 p.m. when a black Chevrolet Impala slowly drove by. Three of the five were walking ahead, with Wilson-Shaw and another companion about 15 to 20 feet behind.

As the car passed, the driver's window was down, and the driver looked directly at the three people in the lead group. The vehicle drove ahead, then turned around and drove back. As it slowed, a passenger in the back of the car fired several shots. The car continued south, then slowed again. Several more shots were fired before the car sped away at a high speed.

Wilson-Shaw was struck in the back and died at the scene.

Investigators for the St. Paul Police Department gang and guns unit tracked the car to Moore's mother and later arrested Moore for violating a domestic abuse no-contact order. He admitted to police that he drove the car during the shooting.

He also identified the men riding with him, but said that he did not know shots would be fired at the people walking on the bridge, several of whom were identified as members of the East Side Boyz gang.

Moore and another man arrested have denied having gang rivalry issues with the East Side Boyz.

Nicole Norfleet • 612-673-4495

Twitter: @nicolenorfleet