Also, it might be the bleeding is more profuse due to medication she takes. I am just offering my opinion here based on past experience with elderly relatives and, more recently, with my husband: he nicked his finger while doing dishes and it looked like a crime scene. When we washed his hand, it was the slightest of cuts...I sent him to the doctor to follow-up; he needed a supplement to help with that.
It happens, but I am sure the CSI would have identified the age of the blood stains (and who wouldn't clean it up ASAP?) and possibly if it was due to a puncture or a slower bleed.
Opinions, all opinions.