SPOKANE, Wash. (AP) — A jury in Spokane, Washington, has convicted a 65-year-old transgender woman of three counts of first degree murder.

Donna Perry will be sentenced on July 24 in Spokane County Superior Court.

Perry used to be known as Douglas Perry before undergoing gender reassignment surgery in 2000.

She was convicted Thursday in the killings of 26-year-old Yolanda Sapp, 34-year-old Nickie Lowe, and 38-year-old Kathy Brisbois. The three worked as prostitutes in Spokane and were all shot during a four-month span in 1990.

The cases were unsolved until 2012, when Perry was convicted in federal court for being a felon in possession of a firearm. Her DNA was entered into a national database and linked to the victims.

Prosecutors contended Perry changed her gender to avoid suspicion.

The jury began deliberations Tuesday.