Man accused of killing mother, grandmother at southwest Miami-Dade home

Arrest report: Marc Mamert, 48, claimed medication made him 'act crazy'

MIAMI-DADE COUNTY, Fla. – A South Florida man was arrested over the weekend after he killed his mother and grandmother at their home in southwest Miami-Dade, authorities said.

According to an arrest report, Marc Michael Mamert, 48, went to the emergency room at South Miami Hospital Saturday and told staff that he did something bad and thought he killed his family.

Police said he claimed his prescription medication made him do it.

Employees at the hospital called 911 and requested emergency personnel. They gave the dispatcher the address to the home provided by Mamert so police could check on his family.

According to the arrest report, authorities went to the home on Southwest 104th Street near 82nd Avenue and found the body of one of the victims inside the home. The victim had been stabbed multiple times, authorities said.

Police said the body of the second victim was found outside the home. The second victim suffered blunt force trauma to the head, authorities said.

The victims were later identified as Mamert's mother, Toni Mamert, and his grandmother, Eleanora Mortalo.

Pia Petrelli has lived next door to the Mamert family for six years and knows them well. She told Local 10 News that Marc Mamert was always a bit trouble, but said this was just sickening. 

"It really shocked me to the point that I could not spend the night at my house," she said. "I had to find a place with my kids because I was truly in shock." 

Police said Marc Mamert was taken to the Miami-Dade Police Department's Homicide Bureau for questioning. 

According to the arrest report, Mamert invoked his right not to speak with detectives without an attorney present, but made numerous spontaneous statements, including that he didn't mean to hurt his family, but that he killed his mother and grandmother because his medications "made him act crazy and blackout."

Mamert is being held at the Turner Guilford Knight Correctional Center without bond. 

 


About the Authors

Amanda Batchelor is the Digital Executive Producer for Local10.com.

Alex Finnie joined the Local 10 News team in May 2018. South Florida is home! She was raised in Miami and attended the Cushman School and New World School of the Arts for high school.