The ACLU of Massachusetts is suing the Boston Police Department for access to its gang database.

Lawyers for the ACLU say police are too secretive about how they track believed gang members, a practice that can have "catastrophic consequences for a young person's life," according to the suit filed in Suffolk Superior Court Thursday.

Boston Police Commissioner William Gross is named as a defendant in the suit, which alleges the Boston Police Department is misusing public records exemption, in an attempt to keep key information about the tracking system private.

"Being labeled as a gang member can have catastrophic consequences for a young person's life, including being targeted for surveillance and police stops, facing harsher outcomes in the criminal justice system, and for non-citizen youth-being detained and deported," lawyers wrote in the suit. "Yet, under BPD rules, police can place children in its 'Gang Assessment Database' and label them as 'active' gang members based on nothing more than the clothing they are seen in and the classmates they are seen with."

In particular, the data is being used increasingly in immigration court, according to the ACLU lawyers.

Lawyers say police use a point system to determine whether or not to add a person to the database. People added to the database are not notified, according to ACLU lawyers.

Ten points place a person in the database as a gang member, while people with six to nine points are labeled as a gang associate.

People can be allotted four points for wearing a Chicago Bulls hat (identified as gang paraphernalia) and two points for appearing in a photograph with a gang member, even if that person is a classmate or family member.

Being the victim of a gang-related act of violence earns a person eight points, according to the suit.

The suit focuses on three young immigrants affected by their placement on the database: Martin, a Salvadoran teenager who fled gang violence and lives with family in East Boston; Lucas, a Central American boy in the process of becoming a legal citizen; and Victor who came to the United States from Central America seeking protection from violence and parental neglect in 2012. The names used for the young men are pseudonyms, according to the suit.

Martin ended up on the gang database because he was a victim of an assault at school and was seen with two other young people who are alleged to be gang members, according to lawyers for the ACLU. He is being detained by U.S. Immigration and Customs Enforcement and his attorney's request to review the database records have been denied, according to the suit.

Though Lucas has never been charged with a crime, he was detained by ICE solely based on the Field Interrogation/Observation/Encounter reports, or FIOEs, that help Boston and school police report potential affiliations. He had a valid petition for permanent status in the United States pending, but now faces likely deportation, lawyers said.

Victor was about to awarded his green card in 2018 when U.S. Citizenship and Immigration Services found that five years earlier, a school officer alleged he was a gang member.

"The government has threatened to revoke its previous approval of his status and deport him based on that allegation," according to the suit.

The ACLU, along with other community organizations, submitted a public records request in May seeking access to the police data.

Boston Police declined to provide certain information including the number of people in the system.

The ACLU is asking the court to issue a declaratory judgment that the records the plaintiffs have requested are public record and to enter a permanent injunction requiring Boston police to disclose all of the records requested.

Boston Police Sgt. John Boyle said the department does not comment on ongoing litigation.