Discuss as:

Cops: Teen stabs grandma, shoots with crossbow

Polk County Sheriff's Office

Jasper Aristotle Smiddie is accused of stabbing his grandmother nearly 100 times.

A central Florida teen is facing first-degree murder charges after authorities say he stabbed his grandmother nearly 100 times, hit her in the face with a wrench and shot her in the back of the head with a crossbow arrow.

Jasper Aristotle Smiddie, 19, was arrested Wednesday morning in Sebring in the brutal murder of his 67-year-old grandmother, Gloria Helfrich, according to Polk County Sheriff's Office spokeswoman Carrie Eleazer.

Helfrich was found by deputies Tuesday at her home in the 4800 block of Wales Street in Lake Wales after receiving a call from Smiddie's father, who told authorities his son had called him to say he'd murdered Helfrich, Eleazer said.

For more, visit NBCMiami.com

When deputies kicked in Helfrich's locked bedroom door in the home she shared with Smiddie, they found a gruesome scene. An autopsy showed she'd been stabbed in the back 58 times, stabbed in the back of her head 34 times and suffered one stab wound to the face, Eleazer said. She had also been shot in the back of the head with a crossbow arrow and had bruising on her face from a pipe wrench.

Smiddie fled the scene in Helfrich's Toyota Rav-4, and was arrested near his girlfriend's parents' house the next day, Eleazer said. His 14-year-old friend and neighbor was with him, and is cooperating with detectives, Eleazer said.

Smiddie was in custody in Highlands County and was expected to be transported to Polk County Thursday, Eleazer said.

More content from msnbc.com and NBC News