Sentencing is set for next week for 35-year-old Miguel Trejo.
Trejo appeared in court Wednesday in Brownsville and admitted to killing Flavia Padron Avaiza last July. Authorities say he barged into her home, beat and strangled her and stole a diamond ring.
He was arrested later that day and charged with capital murder.
While in jail, he also was charged with aggravated sexual assault for an attack on a 62-year-old Harlingen woman in January 2011. The Brownsville Herald reports (http://bit.ly/Jguwvv) she identified Trejo as her attacker.
The life term is for the murder. The concurrent 20-year sentence is for the rape.