A father and son riding motorcycles were shot on the Southeast Expressway near Neponset Circle on Sunday evening, State Police said. Officials said Monday morning that they located the SUV sought in connection with the shooting.

The two riders -- a 54-year-old Raynham man and his son, a 32-year-old East Taunton man -- were driving on separate bikes on I-93 southbound just past 5 p.m., police said. An occupant of a red Jeep Renegade, also traveling southbound, reportedly fired at the motorcyclists on the road just prior to Exit 12.

Both riders were injured. The father was transported to Tufts Medical Center with serious but non-life threatening injuries. His son was in critical condition at Boston Medical Center with life-threatening injuries early Monday morning.

Officials have not released the victims' identities.

The shooter fled the scene in the Renegade, officials said. Large sections of the expressway were shut down during the initial stages of the investigation.

State Police later located and identified the Jeep, which is in a secure processing facility. They are seeking information on the two men seen inside the vehicle.

Anyone traveling in the area of I-93 in Dorchester around 5 p.m. Sunday with any information regarding the investigation is asked to call the State Police Communications Section at 508-820-2121.