by KYW's Brad Segall

A Plymouth Meeting man is expected to go on trial next Tuesday in Montgomery County, Pa. on charges he killed his girlfriend’s teenage daughter last December. And now there is new information that points to him as a suspect in an unsolved triple murder in Philadelphia.

A search warrant requesting a DNA sample from Mark O’Donnell has been unsealed, and that warrant labels O’Donnell (above) as a possible suspect in the murders of William Fowler, his wife Estella, and their 20-year-old quadriplegic son John two years ago in their Port Richmond home (see previous story).
 
Police asked for a saliva sample from O’Donnell to compare with DNA recovered from the Fowler crime scene. Montgomery County authorities said Wednesday that they hadn’t heard back from Philadelphia police regarding a match.

According to the warrant, a witness told police that Fowler argued with a home care nurse named "Mark.” Police later determined that O’Donnell was a nurse assigned to the Fowler home.
 
O’Donnell heads to trial on Tuesday for the murder and rape of 14-year-old Ebony Dorsey (see related story). He faces the death penalty in that case if convicted.