Two young transients have pleaded guilty to killing a Canadian tourist who was camping in San Francisco's Golden Gate Park during a music festival and a yoga teacher walking his dog on popular hiking trail two days apart in 2015.

The Marin County District Attorney's office announced the pleas Monday.

Prosecutors say 24-year-old Morrison Lampley has agreed serve 100 years in prison and 19-year-old Lila Scott Alligood has agreed to 50 years in prison after each pleaded guilty to two counts of first degree murder. Lampley's sentence was double Alligood's because he pulled the trigger in both murders.

Twenty-five-year-old Sean Angold previously pleaded guilty to second-degree murder charges and will be sentenced to 15 years in prison.

The trio robbed and killed 23-year-old Audrey Carey and 67-year-old Steve Carter.