DALLAS - Police believe jealousy played a role in the stabbing death of a man Monday afternoon in Dallas.

Investigators said a man discovered a new boyfriend at his ex-girlfriend’s home in the 2400 block of Bluffton Dr. Police said the ex-boyfriend stabbed the other man to death and then ran from the scene covered in blood.

Bishop Lynch High School, located in the 9700 block of Ferguson Rd., placed itself on lockdown as a precaution while police searched the neighborhood for the suspect, but he was not located.