A Suburban Hospital worker was convicted of murdering a colleague inside the Montgomery County hospital on New Year's Day.
Keith Little hated his supervisor, Roosevelt Brockington, prosecutors said.
Brockington was found in the boiler room of the hospital with 72 stab wounds.
Little was annoyed with Brockington because he wouldn't allow Little to keep a second job, prosecutors said.
Little was accused of another homicide in 2003. He was acquitted after a four-day trial.