APALACHICOLA, Fla. (NewsNation) — An urgent search is underway for a 37-year-old Florida inmate who walked away from his work crew Monday, according to the Franklin County Sheriff’s Office.

State inmate Robert Rutherford walked away from his work crew site at the 10-Foot Hole, also known as the Battery Park Marina boat ramp, in Apalachicola just before 2 p.m. ET, authorities said.

Rutherford is considered “armed and dangerous” after a local resident reported that his shed was broken into and a machete was missing, FCSO spokesperson Sophia Harrell told WCTV.

The escaped inmate has an extensive criminal history, and police have advised residents to not approach him and to keep their doors and vehicles locked.

“Please, if you see him call 911. Don’t wait, call us immediately,” said Franklin County Sheriff A.J. “Tony” Smith.

Rutherford was last seen wearing a solid blue two-piece inmate uniform and is believed to be traveling on foot, police said. Smith said it’s unknown if Rutherford has found a pair of clothes to change into, but the offender has many tattoos on his face, neck and head that can help identify him.

The inmate was serving a 20-year sentence at Franklin County Institution for armed burglary and stealing property worth as much as $100,000, according to state records. He was originally convicted in August 2011 and was 12 years into his 20-year sentence.

Smith warned residents in a video on social media, calling Rutherford a “habitual offender.”

“When someone who is serving a sentence decides to walk away and to run, it is very serious and they are desperate, or they wouldn’t be leaving,” Smith said. “So I caution everybody.”

The FCIO has also asked residents to check any home security cameras to see if Rutherford was spotted on any of them, hoping this could lead to any clues on his whereabouts or where he is heading.

While police are urging residents to be cautious, Rutherford’s sister told The Apalachicola Times that her brother wasn’t a violent man and that the police were painting a picture that could get the inmate hurt.

“He is not dangerous. The police are painting a picture that could get him hurt and that’s not right,” Christian Rutherford said.

She has pleaded with the public for his safe return.

“I just wanted the good people of Franklin County to be aware that my brother is a person with a huge heart and he is not violent,” she wrote. “Please help me find him safely so he can carry out his sentence and come home to a family that has been waiting many years. “

NewsNation affiliate WMBB contributed to this report.