Sheriff's office spokesperson Shari Ireton confirmed Friday evening that detectives had arrested a 26-year-old Marysville man in connection with the nearly month-old case.
The man, who has not been identified, was arrested Friday at his home and booked into Snohomish County Jail on suspicion of first degree murder.
Both Conley's father, John Conley, mother, Susan Arksey, and step-father Matthew Arksey expressed their gratitude to the detectives of the Snohomish County Sheriff's Office for their work.
Her mother and step-father also thanked those in the Lake Stevens community and the Magnolia neighborhood where they live who have supported them.
Conley, a Bishop Blanchet freshman, was walking with friends in Lake Stevens on the night of June 1 when she was shot once in the neck in what police have said appeared to be a random drive-by shooting.
Snohomish County dispatchers used an emergency notification system last week to call about 4,000 phones, seeking information that could help catch Conley's killer.
Prentiss said the recorded calls were answered by nearly 1,500 phones; nearly 1,700 went to voice mail; and about 900 were not answered or disconnected.
The message said detectives are investigating several shootings in and around Lake Stevens the night of June 1 and morning of June 2, including the one that killed Conley.
It's unclear if those calls played any role in Friday's arrest.