The bodies of 11 women were found at his home.
The (Cleveland) Plain Dealer said Cuyahoga County jurors deliberated for 15 hours over three days before returning a verdict of guilty. Testimony went on for three weeks while prosecutors called 62 witnesses. Sowell's defense called no witnesses.
Defense lawyers tried to show the defendant a sympathetic character and raise reasonable doubt in the minds of jurors -- the defense said prosecutors presented no direct evidence: no eyewitnesses, no fingerprints and no DNA linking Sowell to any of the victims, The Plain Dealer said.
But jurors rejected that argument.
Sowell's lawyers will try to convince jurors during the sentencing phase of the trial that he should not face the death penalty. The judge has the decision on whether to impose the death penalty, but only if jurors approve it.
The newspaper said some relatives of the victims began to cry as the verdicts were read.
LGBT community has 'bullied the American people': Bachmann
Handler slams Piers Morgan: 'You're a terrible interviewer'