CLEVELAND: Officials have acknowledged that they may never know how many people were released from Ohio prisons without having their DNA entered into databases that could help link them to other crimes.

Officials know that more than 300 inmates got out without submitting DNA samples in 2012 alone, the Plain Dealer newspaper of Cleveland reported Tuesday. And that includes only the ones who were in prison or on parole when officials began trying to figure out whose DNA was missing.

State law requires that DNA be collected from felons, and law enforcement agencies say it increasingly is allowing them to solve more crimes. The samples can help them put a name to DNA evidence collected at crime scenes or link together multiple crimes by the same person.

State officials say they started looking into the lapse in 2011 when they learned that that DNA collected from convicted Cleveland serial killer and rapist Anthony Sowell was never entered into databases. Sowell was convicted of killing 11 women at his home between 2007 and 2009.

After it was discovered that Sowell’s DNA never made it into the system, the state crime lab undertook a major effort to identify any other lapses, according to Thomas Stickrath, who oversees the Bureau of Criminal Investigation and Identification.

Stickrath said it was a tedious process for his staff to compare hundreds of documents by hand over several months to verify which inmates did or didn’t have their samples in the system.

“It was a one-time thing, very specifically to see if there were any errors,” Stickrath said. He said the thought was “let’s not have another Sowell.”

That effort led to the list of more than 300 people who were in the prison system at the time. The prisons agreed to re-collect samples so the state lab could enter them into the databases.

One of the inmates on the list of 300 to be re-sampled was Larry McGowan, 37, who Cleveland police announced last week had been linked to rapes reported by women on Cleveland’s southeast side in 1996, 1998 and 2010, and a 1997 slaying.

Stickrath said state prisons will be responsible for collecting fewer samples in the future because the responsibility has shifted to hundreds of local law enforcement agencies under the new Ohio law that requires DNA to be collected from anyone arrested for a felony offense.