He was appointed to be a Judge of the High Court in 2003. His 21 years in the judiciary has seen him deliver landmark rulings.
In 2009, he nullified the creation of 256 districts that had over a period of seventeen years been created at the prerogative of both President Daniel arap Moi and his predecessor – Mwai Kibaki.
The Executive had from 1992 created a total of 256 districts in the country in contravention of the law.
Despite the government’s defence, Musinga stood his ground and determined the districts created to be in total disregard of the law. This led to the abolishment of 210 districts, leaving only 46 districts as legally constituted.
In 2011, then-President Kibaki appointed Judge Alashir Vishram and lawyer Githu Muigai as Chief Justice and Attorney General. The appointment came when the then Prime Minister Raila Odinga had jetted out of the country.
After a petition was filed before him, Musinga termed the appointments as unconstitutional, citing failure to consider women for the position and not adhering to set standards for such appointments.
Unlike the norm, when election petitions reached his desk, he did not dilly dally in making the judgement.
In 2008, he declared the South Mugirango seat vacant after finding the election results could not be verified.
The same fate befell then Bomachoge MP Joel Onyancha whose election was nullified in 2009, despite him siding with the government of the day.
In an interview years ago, Justice Musinga stated that he constantly has to look over his shoulder because of his work. However, he does not shy away from upholding the rule of law.
The judge, who many a times has admitted to being a believer, has stated that his delivery on rulings is similar to doing the work of God in his eyes.