The D'amsi are an interstellar police force that maintains law and order within the Cooperative, a highly advanced alien civilization located in the Milky Way Galaxy. Members of the D'amsi hail from the roughly 10,000 planets that make up the Cooperative.
The D'amsi's uniforms are equipped with universal translators enabling them to communicate with the numerous species they encounter. Members of the D'amsi lacking an innate power of flight are also equipped with devices providing self-levitation.
The D'amsi are permitted to leave Cooperative space, which is their usual jurisdiction. This is necessary because they sometimes have to rescue Cooperative citizens or capture fleeing suspects outside their territory. D'amsi are expected to work with the authorities of non-Cooperative worlds within reason during such circumstances.
More discretion is required when the D'amsi must venture onto a culturally primitive world unfamiliar with extraterrestrial life. In these instances, D'amsi use covert tactics to minimize the chance that they will negatively impact that world's culture. To that end, D'amsi use such technology as cloaking devices on their shuttles to conceal their presence.
Ironically, the primitive world of Earth has a played a significant role in the D'amsi's history. The Cooperative first learned of the planet about 100 years ago when a D'amsi ship stumbled across it during a patrol of an uncharted part of the Milky Way Galaxy. After several years, the D'amsi's more detailed survey of the planet revealed that its human inhabitants showed much potential technologically and in the development of metahuman abilities. However, Earth's inhabitants displayed much xenophobia to each other, which made it very likely that they would respond to any Cooperative outreach with fear and hostility. So, 85 years ago, the Cooperative decided to quarantine the planet until humanity became more culturally mature.
This quarantine was broken in recent years when a female D'amsi pursued a notorious Cooperative criminal, who crash landed on Earth. Disguising herself as a human, the D'amsi discovered her quarry was hiding in Dakota City. During her search, the D'amsi's alien nature was accidentally discovered by a human male. After the D'amsi explained her origins and mission, the human decided to not only keep her secret, but help her in her quest. Over time, this unlikely partnership evolved into a romantic relationship much to their surprise.
Eventually, the D'amsi and her human lover cornered the alien criminal just as he was about to take off in his now-repaired spacecraft. To cover his escape, the criminal shot the D'amsi's lover. Desperate to save her lover, the D'amsi used the advanced medical technology on her ship to heal his injuries. The medical procedure not only restored the D'amsi's lover to full health, but also unexpectedly activated his dormant metagene, granting him superhuman powers.
The D'amsi made her lover an unofficial D'amsi by giving him a spare uniform. She also gave her lover a communication beacon that she would use to contact him after she had caught the alien criminal. The D'amsi then left Earth, but her ultimate fate is unknown. As for the human D'amsi, he eventually joined the superhuman gang, the Blood Syndicate, who gave him the alias DMZ.
More recently, during a routine patrol, the D'amsi Evane and Tetras picked up a distress signal from a Cooperative lifepod. The officers traced the signal to Earth's solar system before it abruptly stopped. Evane and Tetras informed the Cooperative of this distress call and that they would investigate further.
Two months later, the signal began broadcasting again, enabling Evane and Tetras to identify Earth as its source. The pair responded to the signal, asking its user to stay put until they could rescue him. As the D'amsi's starship approached Earth, they detected the energy signature of an inertia winder, a Cooperative device, emanating from Dakota City. Taking a shuttle, Evane and Tetras tracked the signature to its source: the armored vigilante Hardware.
Evane and Tetras thought they had found the lifepod's passenger and tried to escort Hardware to their shuttle. (Cooperative lifepods disguise their passengers so they can blend in among the population of a culturally primitive world until a rescue party arrives.) Hardware tried to convince the D'amsi that he was human, but they thought he was delusional. This misunderstanding led to a brief fight that ended when Hardware finally convinced Evane and Tetras that he was telling the truth.
Hardware then revealed that the lifepod's passenger was Augustus Freeman, better known on Earth as the superhero, Icon. Freeman hired Hardware to repair the lifepod's communicator in exchange for access to the craft's technology such as the inertia winder in Hardware's armor. It was Hardware's regular tinkering with the communicator that explained the irregular distress signal that Evane and Tetras detected.
Having cleared things up, Hardware led Evane and Tetras to Icon, who was overjoyed at finally being rescued. Icon then began putting his affairs in order before leaving Earth. Among these affairs, Icon introduced Evane and Tetras to DMZ, whom the former erroneously believed was a stranded alien like himself. DMZ silently declined the offer to go to the Cooperative and asked Evane and Tetras to not report his presence on Earth. The D'amsi agreed and then returned home with Icon, whose tale of survival made him an instant celebrity among Cooperative citizens.
One person not pleased with Icon's survival was Oblivion, a notorious serial killer whom Icon had imprisoned nearly 200 years ago. After escaping prison, Oblivion traveled to Earth to slaughter its population as part of his vendetta against Icon. As Oblivion hoped, Icon immediately returned to Earth while the D'amsi dispatched their nearest available patrol to assist. By the time the D'amsi patrol arrived on Earth, Oblivion had been defeated by Icon and his human sidekick, Rocket. Oblivion was taken back into custody by the D'amsi, who erased all electronic recordings of their visit as they left Earth.
About 50 years before Icon's rescue, the warlike alien race called the Yoongar attacked and destroyed the Cooperative planet, Velda Glenn. After reconstituting Velda Glenn, the Cooperative sent a pair of D'amsi to meet with Yoongar leaders to resolve the conflict peacefully. Unfortunately, the Yoongar viewed this gesture as weakness and fatally shot the D'amsi, who were revived thanks to advanced Cooperative medical technology. The same D'amsi met with the Yoongar bearing a peace offering in the form of a Maker, a Cooperative device that can create matter in any configuration or quantity. Sadly, the Yoongar again shot the D'amsi and took the Maker to upgrade the already formidable armaments on their warships.
After dozens of additional peaceful overtures, it was clear that the Yoongar's planned invasion of Cooperative space could not be diplomatically thwarted. Hence, the Cooperative was on the verge of its first war in nearly 100,000 years.
Once again, the planet Earth played a significant role in galactic history. Shortly after Icon and Rocket's defeat of Oblivion, the Cooperative military strategists learned the Yoongar's route to invade the heart of Cooperative space would take them right through Earth's solar system. The Cooperative rightly feared the Yoongar would callously destroy an innocent planet like Earth simply for being in their path. After learning of her homeworld's impending destruction, Rocket decided to single-handedly take on the Yoongar warriors, a foolish act that required her to be rescued by Icon.
Still, this experience made Rocket realize that the best way to beat the Yoongar was to let them fight a new enemy. Inspired by this clever suggestion, Cooperative leaders deployed a fleet of robotic warships to intercept the Yoongar as they neared Earth's solar system. The Cooperative ships were programmed to constantly fight the Yoongar's warships to a draw. Oblivious to this, the Yoongar kept vainly changing tactics to win against a foe which did not seek to defeat them. This battle continues to this day. Hence, the Yoongar invasion ended before it really began.
- Universal Translator: All D'amsi uniforms are equipped with universal translators that enable them to learn and speak the language of any sentient being they encounter. The process of analyzing and translating an unfamiliar language takes just a few seconds.
- Anti-gravity Devices: Many D'amsi uniforms are also equipped with devices that negate the force of gravity on the their bodies. When activated, these device enable a D'amsi to levitate and thus fly. Some D'amsi like Evane do not use this technology since they can fly under their own power.
- The first Milestone character to appear in a D'amsi uniform was DMZ in Blood Syndicate #1. However, an actual D'amsi would not appear until Icon #8.
- Rocket nicknamed D'amsi "space cops" since she initially did not know what they were called.