Yeah, something doesn't smell right. Such a house certainly has a security system plus it was behind iron gates.
But it was the pistol thrown into the shrubbery that got my attention. Why do such a thing? It doesn't sound like they were being pursued right away.
The bad guy knew she was on the phone...He probably tossed the gun, so if stopped fleeing, he would not have the murder weapon, or any weapon on him. Then again he could have accidentally dropped while fleeing. If he was not wearing gloves, expect to see his photo soon from prints, or from the video security.
I would suspect this guy will be in custody soon either way.