DURHAM, N.C. — Durham police said their second gang unit is having such a positive impact on the city that they are keeping it.

The two gang units investigate drug and gang complaints and conduct gang awareness lectures. They also arrested more than 60 gang members during a 90-day trial period.

According to police, there are as many as 50 different gangs operating in the city.

Four known gang members were charged with murder this week, one of whom remains at large. Police are looking for 20-year-old Deshaun "Smoke" Mitchell, of 3817 Dearborn Drive and 719 Holloway Street.

Mitchell is wanted in connection with the May 6 shooting death of 22-year-old Reginald Johnson on Weaver Street.

Anyone with information on Mitchell's whereabouts is asked to call Cpl. J.N. Cates at

560-4440, ext. 235,

or CrimeStoppers at

683-1200.

CrimeStoppers pays cash rewards for information leading to arrests in felony cases. Callers do not have to identify themselves.