BOSTON -- A Boston cleric and former employee at English High School already facing an attempted murder charge for allegedly shooting a 17-year-old student in the head, has pleaded not guilty to gun and drug charges.

A judge Tuesday bumped bail for Rev. Shaun Harrison by $150,000 to a total of $400,000 following his arraignment on two counts of unlawful possession of a firearm and single counts of trafficking in cocaine, and other charges.

The gun and drug charges came after a search of the 55-year-old Harrison's home. Police found guns and drugs in a safe in his basement. They reportedly found two handguns, a rifle, a shotgun, several calibers of ammunition, cocaine and a large amount of marijuana, according to CBS Boston.

His lawyer said "a number of people" had access to the safe.

Authorities say he was involved in the drug trade and had hired the 17-year-old to work for him until they got into a dispute earlier this month, according to CBS Boston. That night, while they both left Harrison's home, he allegedly pulled out a handgun and pointed it at the back of the teen's head and fired.

Surveillance video captured the incident, according to the station.

Police say the teenage victim was taken to a hospital and treated for non-life threatening injuries. Harrison was arrested the following day.