KITCHENER -- A convicted killer is back in court: Michael Ball pleaded guilty on Monday morning to gun and drug trafficking charges.

The 28 year old admits he trafficked weapons, cocaine and meth between 2012 and 2013.

Court heard Monday that police started watching Ball in the summer of 2013.

At Ball's murder trial earlier this year, police said they started investigating him after Erin Howlett's body was found along the banks of the Grand River in June of that year.

He was convicted in May for the first-degree murder of Howlett.

Around that time, Ball's phone was seized and his home in Kitchener wiretapped.

During that time, police found text messages and heard wire taps indicating that Ball sold guns and other weapons, cocaine and meth.

When asked how he would plea to the charges on Monday morning, Ball said "guilty" four times.

Ball is currently serving a life sentence for the murder charge. He has appealed that conviction.