Nairobi lawyer Assa Nyakundi shot his 29-year-old son in what he reported to Muthaiga Police Station as an accident.
According to the police report, the two had left ICC Church along Mombasa Road and were parked outside their house in Muthaiga.
The lawyer's gun allegedly discharged a single bullet as he transferred it from a pouch to a holster and the bullet lodged in his son's chest.
Mr Nyakundi drove to the Aga Khan Hospital where his son was pronounced dead on arrival.
Nairobi Police Commander Philip Ndolo confirmed the incident adding that investigations were underway to determine what happened.
"It is unfortunate a life has been lost more so his son. We are looking into the incident," he stated.
The lawyer's gun along with 14 rounds of ammunition were confiscated by the police.
Lawyer Assa Nyakundi in high-profile murder case
Mr Nyakundi is the lawyer representing Magistrate Pauline Chesang who is on trial for the murder of her husband, lawyer Robert Chesang.
The lawyer also represented Apostle James Ng'ang'a when he in court over charges of killing a woman through dangerous driving.
Apostle Ng'ang'a was acquitted in the case.