Police in Florida are searching for a 27-year-old man suspected of killing his grandmother and stealing her car Wednesday. Patrick Campbell was named a person of interest after his grandmother, 64-year-old Darlene Robertson, was found beaten and stabbed to death in her New Smyrna Beach home. According to police, the victim suffered blunt force trauma to the head and cuts to her abdomen. Scroll down for video . Wanted man: Patrick Campbell, 27 (left), has been named a person of interest in the murder of his grandmother, 64-year-old Darlene Robertson (right), who was found beaten and stabbed to death . Grisly end: Robertson's son found her lying in a pool of blood in her living room in New Smyrna Beach, Florida, when he went to check up on her . Evidence: Police found Campbell's bike on Robertson's property, leading them to believe that he was at the house around the time of the slaying . Investigators say they found no evidence of a forced entry at Robertson’s home in the 400 block of DeSoto Drive. They believe her grandson, who has been described by friends as mentally unstable, may have been staying with her. Darlene Robertson was discovered lying in a pool of blood in the middle of her living room at around 10am Wednesday by her son, who came to check up on her after she failed to show up for work at a condominium association, according to WFTV. On a 911 call the son told the dispatcher: 'I think she's been stabbed... I think I can see a wound on her stomach.' Responding officers established that Robertson, who lived alone, was last heard from at around 8.30pm Tuesday. Police have found evidence placing Campbell at his grandmother’s home on the night of the murder. His bicycle was found on the property. On Wednesday, police were waiting for a search warrant to enter Campbell’s apartment. They also have reviewed surveillance video from a neighbor’s home, reported The Daytona Beach News-Journal. Armed and dangerous: Campbell is described as unstable and mentally disturbed. Anyone who encounters him is urged to call police . Local authorities have issued a nationwide alert to help locate Patrick Campbell, who is considered armed and dangerous. Anyone who recognizes him is asked to call police right away, as the 27-year-old is believed to be unstable. ‘I think that it’s safe to say that he is not of his right mind,’ New Smyrna Beach Police Chief Mike Coffin said. Henry Toland, a long-time friend and former roommate of Campbell's, described the man as delusional to the station WESH-TV. Other people familiar with the 27-year-old suggested that he may be schizophrenic. Detectives are also searching for Darlene Robertson' missing car, a 2006 beige or tan Nissan Altima with Florida tag 803MBW. A $1,000 reward is being offered for information leading to Campbell's arrest. The person of interest has a past criminal record, which includes at least four arrests since 2011 on charges of trespassing, DUI and marijuana possession.
Patrick Campbell, 27, named a person of interest in murder of his grandmother, 64-year-old Darlene Robertson . Woman was found by her son in a pool of blood in her New Smyrna Beach, Florida, home . Police say Robertson suffered blunt force trauma and cuts to her stomach . Campbell is considered mentally unstable and anyone who encounters him should call police .