SAN ANTONIO (AP) - Experts say technology and an expanding DNA database have helped solve more crimes in Texas.

The San Antonio Express-News reported Wednesday that 643 homicides are among the Texas cases solved with assistance from the Combined DNA Index System, or CODIS.

Department of Public Safety director Steve McCraw says many crimes might never have been solved if not for the DNA database. Registered sex offenders, convicted felons and youths in the Texas juvenile justice system must provide samples.

Texas averaged about 200 matches annually during the first five years after the national database was created in 1996. Records show that number rose to an average 1,000 hits annually for the next 10 years.

The Harris County Institute of Forensic Sciences uses computer automation to help process about 400 samples monthly.

(Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)