LOWELL (CBS) – It was a statement loud and clear outside the Lowell office of the Middlesex District Attorney. “Plain and simple, we want DA Marian Ryan to recuse herself and call in the FBI for a complete and thorough investigation,” said protester Keren Prescott.

Some are calling for Ryan to step down from the office altogether, claiming she’s mishandled the investigation into the death of Hopkinton teen Mikayla Miller.

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Her mother Calvina Strothers says she wants truth and accountability. “I appreciate everyone being here. I’m very grateful for the continued support of my family and finding justice for my daughter,” said Strothers.

Miller’s body was found on April 18 hanging from a tree in woods near her home. These protesters refuse to accept amedical examiner’s conclusion that she died by suicide. “She was found on a tree that would not support her body weight first of all,” said protester Antuon Castro Del Rio.

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They claim investigators have not been forthcoming about an assault on Miller by several teens the night before she died. The district attorney says there’s no proof any of those teens were near her in the woods, but the protesters say they won’t stop until there’s an independent investigation, not the district attorney leading the probe.

“You have proved you cannot function in a place of professionalism and have the transparency and accountability this family deserves,” said Monica Cannon-Grant, the protest organizer.

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DA Marian Ryan had no comment on the protesters’ demands and says it remains an active investigation.

Beth Germano