Born in Baltimore and raised on Parklawn Avenue, he attended Shrine of the Little Flower School and Archbishop Curley High School. He later took emergency medical training courses at the Community College of Baltimore County at Essex.
"It was his dream to become a firefighter from the time he was 9 years old," said his father, Frank Manieri of Towson.
Friends at the Fire Department said that as a boy, he was known as a "house cat," a term for a person who is a frequent presence at a neighborhood fire house but is not a member.
He began hanging out at the Mannasota Avenue fire station in Belair-Edison and spent much of his free time there.
"As a child, he had a deep fascination for firetrucks and the fire service," said a friend, firefighter-paramedic Michael Hineline, a city resident. "At that time, his life revolved around the place, and he followed the trucks on his bike on calls."
As an emergency medical technician, he became an Advance Care Ambulance Co. driver and attendant. He also joined the Rosedale Volunteer Fire Department and became a volunteer at Bea Gaddy's food pantry.
He then became a civilian Police Department employee. He answered 911 emergency calls for a year before joining the city Fire Department. He graduated from the fire academy and became an apprentice firefighter-paramedic. In 2001, he became a cardiac rescue technician.
According to a department biography, he was promoted to firefighter-paramedic in July 2002 and assigned to Park Heights' Engine Company 29. There he was also named an acting pump operator and fire lieutenant. Department colleagues said the fire company was one of the city's busiest.
"They ran a lot and saw plenty of service," said Rod Devilbiss, a retired deputy chief.
Mr. Manieri won a Distinguished Unit Citation for his work with students at Park Heights public schools. He also belonged to a special-events team and visited children in hospitals during the holiday season.
He was later appointed to a post at Fire Department headquarters and worked in its human resources division. He was awarded the Grecco Labor Award for his efforts "to buttress the relationship" between labor and management.
"He was the go-to man for anything involving pay grades. He was a great problem-solver, and at the same time he absolutely refused to do anything that was unethical," said Mr. Devilbiss, who lives in Pasadena. "He was a humble guy with a dry sense of humor. He was ready with a grin and a quick quip."
In 2009, he was given an Appreciation Award at the Fire Department's annual Medals Day Ceremony.
"I never heard him raise his voice," said Mr. Hineline, a fellow firefighter. "He was respected for the quality of his work."
Friends said he had an "encyclopedic knowledge" of Baltimore street names, locations and Fire Department history. They said he was a champion of Baltimore City life and was a devotee of John Waters films. He enjoyed music and was a fan of the B-52s. He also liked trips to Baltimore diners, including the Sip & Bite and Paper Moon, as well as the Cafe Hon restaurant.
A Mass of Christian burial will be offered at 11 a.m. Monday at Shrine of the Little Flower Roman Catholic Church, 3500 Belair Road.
In addition to his father, survivors include his mother, Mary Manieri of Towson; and two brothers, Matthew Manieri of Haddonfield, N.J., and Andrew Manieri of Yellow Springs, Ohio.