Tokusou Sentai Dekaranger (2004)

Both shows have a police/detective theme where the protagonists solve cases involving crimes committed by the villains of their respective series.

It's the 27th sequel of the series from Super Sentai right after Bakuryuu Sentai Abaranger which is the 26th sequel. If you would like to watch the super sentai series chronologically.

It's the 28th sequel of the series from Super Sentai right after Tokusou Sentai Dekaranger which is the 27th sequel. If you would like to watch the super sentai series chronologically.

Both are Police themed series
Both are fighting against a crime organization
Both have a mix of both mature and silly tone
Police rangers are red, green, and pink

Both are space detectives
Both crossed over in a movie
Both appeared and teamed up with Kyuranger and Gokaiger

Both met and teamed up with Kyuranger and Gokaiger
Both are space detective series
A follow up movie

It's a follow up to Dekaranger
Shows what happened to the cast 10 years later
Cast and head writer returns

A movie based on the source material
A mystery crime movie with the cast
Came out the same year as the show

Both are detective theme shows
Both have the same team color pallet
Both have crime organization villains

It's the very first Super Sentai series what made many of it's successors possible. If you want to watch the original first season of the Super Sentai series.