"He set the tone for a lot us, especially people coming up in this field, this duty for public service," said Wallace Maines, a friend of 49-year-old Peek, who also worked with him as a medic.
Police say early Sunday morning, Officer Peek responded to Bridegton Fire Department's training facility, where a woman hit an ambulance, shattered windows, and tried to break into a trailer.
A warrant says 29-year-old Sarah Davis caused up to $1,000 in damage before she either jumped or fell into the river next to the building.
Police say Officer Peek jumped in to save her, but had trouble getting to shore with all of his equipment.
"To law enforcement, there really is no difference, you raised your right hand and took an oath to protect people's lives and that's what he was doing and in doing so, he made the ultimate sacrifice," said Col. Pat Callahan of NJ State Police.
Peek's wife, Megan, said she's not surprised he did what he did -- sacrificing himself to save someone else. Megan says her husband loved beind a dad.
"He was very hands-on. Anything, play barbies? We'll do that. You want to play board games? We'll do that," she said.
Right now, Megan is doing her best to stay strong for her 8-year-old daughter Katherine.
"She's worried that, for me to go to sleep, that I'm not going to wake up. So she checks on me every morning," Megan says.
Officer Peek and Davis were both treated at a hospital. Davis was charged with burglary and other crimes and Officer Peek went home. Later that morning, police say he was found unresponsive. His cause of death is pending an autopsy.
"Even though she was doing things she wasn't supposed to, he was worried that she was going to be in trouble. He would have done anything, and he did, to help her," Megan said.
Chief Michael Gaimari said in a statement, "Sean was a fine officer and a friend to all and always acted in an exemplary fashion when representing the department and the City of Bridgeton."
His friends say they hope his legacy of service lives on.
"There are good guys out there and there are people who put their life on the line every day and that not a person who goes to that job at any point thinks they're not going to come home, but essentially, you're at that risk of a lot of the time," said Maines.