Prosecutors have charged 27-year-old William Mwanza Maingi with the shocking November killing of James Mack, who met his grisly end on the porch of his own home.
The scene of this chilling crime? The Centennial home Mack shared with his mother, Alice Nimz. According to the Multnomah County District Attorney’s Office, Maingi now faces charges of second-degree murder and illegal firearm possession, with the latter charge stemming from his status as a convicted felon.
The story unfolded on the night of Nov. 25, when Nimz, inside her home near Southeast 154th Avenue and Powell Boulevard, was startled by the sounds of her son in a heated argument right outside her door. In a desperate bid to save her son, Nimz opened the door and tried to pull Mack to safety, but to no avail. The argument culminated in two fatal shots, one to Mack’s stomach and another to his head, leaving the 50-year-old, who had only recently been released from prison, lifeless on his own doorstep.
While the court records remain tight-lipped about the specifics of that fateful night or the nature of the relationship between Mack and Maingi, the grand jury’s decision came after hearing heartbreaking testimony from both a Portland police detective and Nimz herself.
Maingi’s arrest in the early hours of Sunday adds another dark chapter to his criminal history. Back in 2016, he was convicted of three counts of second-degree robbery related to a series of robberies across Portland, Gresham, and Beaverton. Now, locked away in the Multnomah County Detention Center, Maingi awaits trial for a crime that has left a community in shock and a family shattered.
This tragic story raises as many questions as it does emotions, with a mother’s grief at its center and a neighborhood grappling with the reality of violence on its doorstep. As the case against Maingi progresses, the eyes of Gresham and beyond are fixed on the unfolding drama, waiting to see what justice will be served in this midnight murder mystery.