Local and federal law enforcement are working to identify members of Tren de Aragua (TdA) in Colorado. But determining whether someone is a member of the notorious gang is challenging.Aurora Police Chief Todd Chamberlain said theres no doubt some of the suspects arrested for the recent kidnapping and torture of a couple at an Aurora apartment complex are gang members."When you look at the individuals involved in this, when you look at the veracity and the violence involved in this, again, it is not a big step for me to say that they are TdA gang members, Chamberlain said. Identifying TdA gang members in Aurora presents challenge for law enforcementHe said while some suspected gang members may make it easy for law enforcement by admitting to being a member of a gang, others dont.It's never been a denial that TDA is here. It's never been a denial that there's not a gang problem in Aurora, because there is a gang problem in Aurora, Chamberlain said. The TdA is so challenging because there is very limited information about them. There is very limited, if any, self-identification.Mike LaSusa with InSight Crime told Denver7s Colette Bordelon that Tren de Araguas lack of identifying symbols makes spotting its members even more challenging."They don't necessarily have identifiable tattoos, LaSusa explained. There's not really identifiable symbols that they use consistently across the whole gang."Watch that report in the video below: Organized crime expert explains challenges of identifying Venezuelan gang membersA 2020 study found law enforcement agencies in different regions take different approaches to identifying gang members.It found law enforcement in the West were significantly more likely to identify gang members through associations or arrests with known gang members, symbols and self-nomination compared to other regions. The South, Northeast and Midwest regions are significantly more likely to identify gang members through a reliable informant compared to the West.Investigators also often rely on law enforcement databases to help identify gang members.The databases, which are operated by various local, state and national agencies, can tell police if someone has been identified as a gang member in another jurisdiction.But government watchdog groups say the information is sometimes unreliable.A 2019 report by Chicagos inspector general found the Chicago Police Departments database, which was accessed by over 500 agencies, including the FBI to help their investigations, was riddled with errors."Over 15,000 individuals designated as gang members by CPD had no specific gang membership listed and no reason provided for why the individual was listed as a gang member. Individuals designated as gang members are not notified of their designation and have no ability to appeal the designation," the inspector wrote.Chicago eventually got rid of the database following the report, but the findings highlight why civil rights groups are concerned about law enforcement using such databases.In a 2017 advisory for advocates, the Immigrant Legal Resource Center (ILRC), said information found in gang databases is often stale, inconclusive, or inaccurate.The use of gang databases by law enforcement authorities is problematic for a multitude of reasons, the advisory said. First, many databases have very low thresholds for inclusion, including criteria such as living in a certain neighborhood, appearing in photographs with gang members, talking to gang members, or merely wearing certain colors, which can disproportionately target individuals who live in areas with significant gang activity often lower socio-economic neighborhoods with high numbers of immigrants,ILRC said in some cases, convictions arent necessary for someone to end up in a database.Further, many gang databases fail to purge names of suspected gang members after the period required by state, local, or federal law, the advisory said. Moreover, gang databases generally do not provide individuals with notice or an opportunity to challenge determinations.LaSusa said he would like more information about how Aurora and other law enforcement agencies in the U.S. are identifying TdA members, since the Venezuelan government is in no position to share information given the countrys ongoing political crisis.I think it's also possible that some of the people that have been identified as Tren De Aragua members here in the United States may be misidentified, LaSusa said.Aurora police said no one was available on Monday to talk about its process identifying immigrant gang members.At a press conference on Friday, Chamberlain said Aurora was working closely with Homeland Security Investigations, which is the investigative arm of the U.S. Department of Homeland Security.It is not going to be an easy process. It is going to be a challenge, but we are not going to stop, Chamberlain said.