CLAYTON, Mo. (AP) — Authorities from several St. Louis-area jurisdictions believe they’ve solved a serial killer case that dates back more than three decades. Prosecutors from Lincoln, St. Charles and St. Louis counties on Monday announced four new counts of first-degree murder filed against 73-year-old Gary Muehlberg, who already is serving a life sentence for a fifth, and apparently unrelated, killing. DNA evidence led to the new charges, which accuse Muehlberg in the deaths of four women who were all strangled. All four disappeared in 1990. Prosecutors credited dogged police work, especially by O’Fallon, Missouri, Detective Jodi Weber, who reopened the case 14 years ago.