ST. PAUL (AP) — St. Paul police suspect a 31-year-old man killed his wife and 18-year-old brother-in-law, but authorities still don't know how the husband died.

The Ramsey County medical examiner's office ruled that 27-year-old Pahnia Yang and her brother, Kong Meng Lee, died of injuries caused by a sharp object. But the cause of death of Yang's husband, Chue Lor, has not been determined.

Investigators suspect Lor killed his wife and brother-in-law in a domestic altercation. Police are not seeking any suspects in the deaths.

Police went to an apartment building Sunday afternoon after getting a 911 call. Officers found Yang and Lee fatally injured and also found Lor dead.

No other information is expected to be released until toxicology tests are completed.