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.
"My passion is dogs. It has been since I was a little girl," said Wright. "I read books. Love shepherds, love K-9 units. So, when this opportunity came about, love to do it."
The five-pound vest is heavy and hot, but Marcos took it in stride.
Wright says the vest comes with extra protection.
"The day after I finished raising the funds we lost our bulldog Mojo," said Wright. "It was great to engrave his name. He's a bulldog in heaven looking over Marco."
Wright made the donation from the profits she earned selling Silipada Jewelry.
Out of 18,000 police departments nationwide, she chose HPD because she was awarded a trip here by the jewelry company. She's also donating a second vest which is being custom-fitted for another HPD K-9.
Go to the Vested Interest in K-9s website to donate to the cause.