State police said several people called the Newbury barracks to report a badly injured woman was in the median strip of 495 near Broad Street. The Merrimac Police and Fire departments went to the scene and Rivera-Guerra was transported by ambulance to Anna Jaques Hospital. From there, she was flown by helicopter to Tufts Medical Center.
Trooper Scott Grimes interviewed Rivera-Guerra at the hospital. Grimes found Moises Matos in Lawrence and arrested him at 7:30 a.m. Tuesday, according to Carrie Kimball Monahan, spokeswoman for the Essex District Attorney’s Office.