Recent spike in deadly crimes reflects personal, financial problems, experts say. The recent spike in deadly crimes locally, including a series of horrifying family bloodbaths, likely reflects the frustrations of people lashing out amid personal and financial woes, experts say. There have been seven murders in Norfolk County in 2009, the deadliest toll in at least four years. Deadly crime tends to spike in periods of economic distress, and family members are often the most convenient target, experts said. Cuts in services to the mentally ill also may be preventing at-risk individuals from obtaining treatment, said Kevin Borgeson, a Carver resident and criminologist at Salem State College. “Most of the extreme (crimes) have been issues of mental illness,” Borgeson said. “You probably see more people falling through the cracks in bad economic times.” Locally, most of the alleged victims were close to their attackers. Kerby Revelus, 23, of Milton was shot and killed by police in March after stabbing to death his sister Samantha, 17, and decapitating his 5-year-old sister Bianca. Friends said Revelus had taken a turn for the worse after serving a five-month jail sentence for weapons violations.“It occurs when people become frustrated and don’t know what to do and take out their frustrations on the nearest person,” said Stuart Clayman, a licensed psychologist from Brighton. “People who are violent will also choose as their victims people who are least able to retaliate.” In April, a Quincy mother of three, Fang Chi-Xue, 43, allegedly killed her 9-year-old daughter and 71/2-month-old unborn child. The woman thought her husband had fathered a child with a mistress, investigators said. Early last month, lawyers in the case agreed that Xue is mentally unfit to stand trial. She is committed at Worcester State Hospital. Also in April, a 76-year-old Quincy man was accused of hitting his sleeping 13-year-old granddaughter with a meat cleaver. Man Luc has been sent to Bridgewater State Hospital for psychiatric evaluation. Also in April, there was a domestic murder-suicide at the Motel 6 in Braintree and a homeless man was stabbed to death in Weymouth. Scott T. Steadman is charged with murdering Ronald Pratt, 49, in a tent where he had been living in Weymouth. Clayman, who performs mental health evaluations on people applying for disability benefits, said many of his clients come from households rife with abuse. “People feel more frustrated and angry. Maybe they lost the house or got kicked out of their apartment because they can’t get even low-level menial jobs, and the frustration builds up,” he said. “Some of them use alcohol and drugs to self-medicate themselves for the stresses that build up.”The most recent deadly incident occurred Aug. 29 in Quincy. Police say Joseph Beatty, 52, strangled his 33-year-old girlfriend, Mary Beaton. Beatty told police the two had argued over an upcoming trip to Las Vegas and over money for Beaton’s rent. Prosecutors said Beatty went to Boston Medical Center the day of the murder because he was feeling suicidal, and told staffers there that he had hurt Beaton. According to his defense attorney, Beatty had been a printer and glass installer before going on disability a year ago because of kidney disease.“There’s a lot more stress and pressure now,” said Robert Mendoza, a psychologist for Boston Forensic Associates in Dedham. “When they are left out in the open with no means to cope, it’s very difficult for people. It’s not something they’re used to. There are not many options, and unfortunately, they go home with that.” Steve Adams may be reached at firstname.lastname@example.org.