MERION, Pa. (CBS) – Montgomery County authorities are providing a clearer picture of what may have gone on inside that Upper Merion house over the weekend where a 23-year-old man allegedly killed his father, mother, and twin brother (see previous story).

Montgomery County district attorney Risa Ferman says it appears there was an intense struggle between the defendant, Joseph McAndrew, and his twin brother James, whom Ferman says may have been trying to protect his parents.

But at this point, she says, they don’t have a motive for why Joseph allegedly stabbed the three of them to death Saturday night with some sort of sword.

Listen to Montgomery County DA news conference …

“Clearly we know that there is some aspect of mental illness that the defendant has suffered throughout the course of his life, but there is really nothing at this point that can tell us why these events transpired — what happened to provoke them — and really what was going on inside of his head at the time,” Ferman told reporters on Monday morning.

Reported by Jericka Duncan…

She paints a picture of twin brothers who went down very different paths. She says James graduated Penn State and had a bright future, while Joseph struggled after high school, did not go to college, and was somewhat of a loner.

Joseph McAndrew remains behind bars without bail.

Reported by Brad Segall, KYW Newsradio

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