These are the relationships of the Police Commissioner
The Police Commissioner and the Ninja are allies when it comes to saving Ninjago City.
In the Alternate Timeline, the Ninja and Commissioner were enemies as it was presumed the Ninja committed crimes. However, when he figured out the Ninja were innocent, he became allies by saving Cole, Lloyd, and Nya from Tiger Widow Island. Later, he offers his entire department to the Ninja which became useful in "Wishmasters" as Jay and Nya were able to escape from Flintlocke. When Nya was captured by the Sky Pirates, Jay offered the Commissioner a spot as Ninja Replacements and he agreed. Although he was never able to make it onto the floating piece to Djinjago, he was able to arrest one of the spies.
During Season 8, they come to him for help and he allowed the Ninja to use his police force as a diversion, so the Ninja could sneak under the Royal Palace. After the Ninja defeated the cult, he had his officers arrest the villain and thanked the Ninja.
During Season 9, he was arrested by the Sons of Garmadon because of his affiliation with the Ninja. After getting word they returned, he alongside other prisoners would break out of Kryptarium Prison, and help the Ninja take down the Colossus. Afterwards, he thanks them for saving the day again. He is also present at the ceremony, telling the Ninja that the citizens wanted to thank them personally.
During Season 10, the Commissioner and his crew would off fallen into the darkness, but the Ninja save him.
Simon works as a detective and has a close relationship with the Commissioner.
Through Skybound, Simon took a loosen approach to his job and often told the Commissioner about obvious things such as his eye twitching in odd situations.
In "The Last Resort," it was revealed that the Commissioner likes Simon more than Tommy.
Tommy works as a detective and has a close relationship with the Commissioner.
In "The Last Resort," it was revealed that the Commissioner likes Simon more than Tommy after he revealed that Jay and Nya have the Tiger Widow Venom.
Jimmy has a close relationship with the Commissioner.
During the Oni Invasion, the Commissioner was painting his boat before being interrupted by Jimmy, who tells him there is trouble in the city.
In Season 11, he constantly interrupts the Commissioner about false reports.
At the beginning of Skybound, Ronin is hired by the Commissioner to capture the Ninja. Ronin then accompanies the Commissioner when rescuing the Ninja from Tiger Widow Island. Because of Jay's last wish that undid the events of Skybound, this was forgotten.
During Skybound, the Police Commissioner, Simon, and Tommy were taken captive when he refused to give Jay and Nya location. Nadakhan then threatened him to send either Simon or Tommy to walk the plank. The Commissioner chooses Simon causing Tommy to get upset and accidentally reveal that the Ninja still have the Tiger Widow venom. The trio then jump into the ocean only to be surrounded by sharks. Because of Jay’s last wish that undid the events of Skybound, this was forgotten.
He and his officers raided the building and arrested Harumi and her minions. However, they don't locked up for long after Garmadon is resurrected and liberates them.
It is shown in "Firstbourne," the Commissioner and countless civilians of Ninjago affiliated with the Ninja were arrested.
During "Green Destiny," he hears the Ninja returned and broke out to aid them. Afterwards, he personally taunts the defeated cult on their predicament, in revenge for them having him locked away.