Michael Jackson’s doctor, Dr. Conrad Murray, was convicted Monday of involuntary manslaughter for administering a lethal dose of a powerful anesthetic, which killed the singer in 2009, according to the Associated Press.

The 58-year-old Houston cardiologist could face up to four years in prison and may lose his medical license.

The jury deliberated for less than nine hours. During the six-week trial testimony was heard from medical experts, household employees and Murray’s former girlfriend, among others.