A jury on Monday convicted a 20-year-old Auburn man of two counts of second degree assault with firearm enhancements for his involvement in a shooting on July 3, 2010 in Auburn that seriously injured two women and a man.

Gustavo Gallegos, who was 17 at the time at the time of the shooting, was prosecuted as an adult. The jury returned a guilty verdict against him on the assault charges in connection with the two injured women but found him not guilty on a third charge of assault for the male victim.

Prior to trial, Gallegos pleaded guilty to a charge of second degree unlawful possession of a firearm.

Gallegos faces a sentence of 7 and 1/2 years in prison at his sentencing in October.

A co-defendant, Gallegos’s 15-year-old brother, was charged and convicted of assault in Juvenile Court and will remain in custody until his 21st birthday. The Auburn Police Department investigated the case, and Deputy Prosecuting Attorneys Steve Herschkowitz and Wes Brenner prosecuted it.

According to court papers, a dispute between two young women at a party earlier that evening in the Lake Tapps area may have prompted gang-related threats that led to the shootings. According to court papers, one of the women who’d been involved in the verbal altercation called her boyfriend, 17, to advise him of what had happened. The young woman, her boyfriend and five other peoplethen piled into a Honda and drove to the Gallegos house.

The boyfriend knocked on the door, got no answer and was walking away when somebody shot at him through a window, wounding him in the head and shoulder. The Honda fled along Auburn Way South with the Gallegos brothers in hot pursuit. Court papers say Gustavo Gallegos fired shots from the left rear passenger seat, hitting Ana Martinez-Adriano, who was pregnant, through her left breast, and Jessica Sanchez in her stomach. The people in the Honda were unarmed.

According to charging papers, Martinez-Adriano passed out and the other people in the vehicle thought she was dead. According to court papers, the Honda’s driver pulled into the gravel parking lot of the 76 station at 600 Auburn Way S., where somebody pushed Martinez-Adriano out of the car and onto the ground. After one of the party advised the station’s clerk that there was a dead woman outside, the Honda took off. A short time later Sanchez realized that she had been shot in the stomach, and the driver headed to Auburn Regional to seek medical attention for her.

After a police chase, officers used a PIT maneuver to stop the brothers’ car in the 4000 block of Auburn Way North. Police found a rifle inside the Mustang.

The youth who was shot and Martinez-Adriano were transported to Harborview Medical Center with life-threatening injuries. All three victims survived, but with critical injuries.

According to a search warrant served on the Gallegos home, police later found many gang-related items, in addition to two more weapons and ammunition.