Mount Vernon police say an ex-convict and four others are in custody for a fatal stabbing that took place last month.

Police arrested 27-year-old Rasaun Sanders Tuesday for the murder of Douglas Williams. Police found Williams, 16, stabbed three times at North 8th Avenue and Valentine Street on May 18.

Authorities say Sanders and the four others, who have also been arrested, fatally stabbed Williams because he was part of a rival gang. They add that Sanders is a member of the Crips street gang and that Williams was targeted because he was in the Bloods.

The victim?s mother, Miriam Williams, denies that her son was a member of any gang.

A candlelight vigil in honor of Williams will take place Friday, marking one month since the murder.