It's been two years since a gunman opened fire on Orlando nightclub Pulse, claiming 49 lives - many of whom were LGBT+ people of colour.

At the time, the massacre was the deadliest shooting by a single assailant in American history. Investigations soon found the attack to be an act of terrorism perpetrated by 29-year-old Omar Mateen, a New York-born security guard who pledged allegiance to the Islamic State during his three-hour battle with police officers.

He was eventually shot dead at the scene of the crime.

Now, almost two years later, a group of more than 30 plaintiffs are rallying together to sue the city and its police officers, whom they accuse of violating victims' constitutional rights by not doing enough to stop the shooter. Many of the plaintiffs are survivors of the horrific massacre; another is police officer Omar Dalgago, cited as one of the first to respond and pull people to safety. He was later fired from his job due to PTSD.

According to CBS News, the lawsuit lists numerous complaints, the most serious of which are levelled Orlando Police Department officer Adam Gruler. The document states that the police officer "abandoned his post" at a crucial moment, allowing Mateen to walk inside, scope out the club and return with weapons in hand. Another claim is that the officers "chose to disregard the safety of the patrons while instead ensuring that they themselves were safe".

Gruler eventually fired the fatal shot that killed Mateen, earning him a reputation as a hero. The officer was working "extra duty" on the night of the shooting, supplementing his income with a security shift at the club.

Earlier this year, he broke down in tears as he recalled the events as a witness at the trial of Mateen's widow, Noor Salman. He remembers realising that his firepower was no match for Mateen's assault rifle:

There was no concept of any time for me. No matter where we stepped, there was blood.

Gruler is the only officer named in the lawsuit, but a grand total of 31 defendants are listed for various reasons; some are criticised for not capturing the shooter, whereas others face consequences for the seemingly insensitive decision to round up uninjured survivors for questioning at the local police station. Detainees were also not allowed to use their phones or call loved ones, despite the fact there was no evidence to suggest they had committed any crime.

Keinon Carter, one of the victims behind the lawsuit, gave more detail at a press conference on Thursday, claiming:

I believe victims of the Pulse shooting deserve better. We deserved better. We deserved to be rescued sooner by law enforcement.

Berto Capo, whose brother Omar was shot dead, also claimed that police should have intervened before Mateen was inside the building:

What if the Orlando police officers who responded to the shooting were aggressive with their plan to rescue victims and hostages and kill the shooter - would my brother still be alive?

The defendants have since issued an official response, claiming not to have seen the lawsuit.