Howard County police continued to look this week for four sex offenders after a search failed to locate them at the addresses listed on a statewide registry of convicted child abusers and other sex offenders.

Local police decided to conduct an unannounced check of the addresses of 76 offenders in Howard after a murder case in nearby Baltimore County raised questions about the accuracy of data in the state's registry of more than 4,300 sex offenders.

"We determined that we could not guarantee they were notifying the department when they moved or changed jobs," said Howard County Police Chief G. Wayne Livesay.

Nine of the 13 sex offenders who were not accounted for during the late-July sweep were arrested or turned themselves in as of Tuesday morning. Under the current system, offenders are required to provide their addresses, but law enforcement officials are relied on to check the accuracy of the information.

Howard police used financial and personal records last month to search for the missing offenders. "We're using a number of resources," said David Proulx, county police spokesman. "It's similar to finding a missing person."

"They know now they'll get spot-checked," he said. "This has proven to be an effective tool."

The four offenders still missing were last registered at addresses in Columbia. They were identified as Anthony Thomas Davis, 24; Allen Lawrence Evans, 52; Karen Diane Hammond, 40; and Ricardo Alonso Lewis, 40. Since 1995, the year after Congress passed Megan's Law, Maryland has required sex offenders to register their location with police. The law was named for a New Jersey 7-year-old who was raped and killed by her neighbor, a convicted pedophile.

Registrants who do not keep their information up-to-date face misdemeanor charges, punishable by imprisonment of up to three years and fines of up to $5,000.

A complete list, including the names, pictures and registered addresses of sex offenders in Howard County can be found at the county police Web site,

In the Baltimore County case, Carl Preston Evans Jr., 35, a convicted rapist, was suspected in the July 25 death of his 13-year-old stepdaughter in Essex, but authorities could not find him. As with at least 500 others on the registry, Evans' address was questionable, said Mark Vernarelli, a spokesman for the Maryland Department of Public Safety and Correctional Services.

Evans was arrested Friday by Baltimore County detectives after a foot chase in Baltimore. He has been charged with first-degree murder.

Meanwhile, Gov. Robert L. Ehrlich Jr. (R) has asked state officials to ensure that the registry is more accurate. The state plans to introduce a computerized system that would allow authorities to update information about sex offenders online instead of using a mail-based system.