JEFFERSON COUNTY — Jefferson County prosecutors and detectives are investigating the possibility that a man wanted in connection with a 2010 shooting death on a Mt. Vernon street died before a warrant for his arrest was issued last week.

According to Jefferson County State’s Attorney Doug Hoffman, he filed First Degree murder charges last week against 37-year-old Edward Gilbert, of Chicago, and 36-year-old Dwaine McDonald for 15-year-old Deon Feggins murder.

Hoffman says the charges allege that on August 8, 2010, Gilbert and McDonald shot and killed Feggins as he rode his bike on Conger Street in Mt. Vernon. McDonald turned himself in to the Jefferson County Sheriff’s Department on Sunday.

X95 Radio received information Monday that in October 2015, Gilbert died suddenly in Cook County. Hoffman said he had received similar information and that his office and detectives were investigating the matter.

Hoffman’s February 18, announcement about the arrest warrants came just two days after 29-year-old Marventi Palmer pleaded guilty to Second Degree murder in connection with Feggins death and was sentenced to 10 years in prison.