At a crime scene, sometimes they are the first line of defense -- the Honolulu Police Department's K-9 crew.
One four-legged officer received some much-appreciated protection on Tuesday.
Marcos is one of HPD's 11 dogs that make up their K-9 team.
To the department, they are much more than dogs.
"They're bomb detection dogs, drug detection dogs. They also go out and look for cadavers," said Honolulu Police Chief Louis Kealoha. "They actually go in where the police cannot go in, where it's too dangerous for a police officer to do it. That's the importance of them. They're heroes."
Police officers are required to wear bullet vests. But, at more than $1,000 per vest, dog vests are not part of the HPD's budget.
Through donations, the non-profit Vested Interest in K-9s, Inc. provides the protective vests for law enforcement dogs.
Two ballistic-stab protection vests were donated to HPD last year.
On Tuesday, Marcos was given a form-fitted Kevlar vest, just like his human partner wears.
Massachusetts resident Janice Wright made the donation and was on hand to see Marcos wear it.