A ping from the cellphone of a behavioral health worker who randomly killed a Cleveland grandfather and posted video of the execution on Facebook has been detected in Pennsylvania, according to a report. The clue emerged as police in Ohio urged residents in Pennsylvania, New York, Indiana and Michigan to be on the lookout for Steve Stephens, 37, who may have fled Cleveland after allegedly gunning down Robert Godwin Sr., 74. Stephens’ cellphone ping was detected about 100 miles east of Cleveland in Erie, Pa., authorities told CNN. Police in the city told The Post they were not investigating the...