ELMWOOD PARK — Investigators are still trying to determine why a 100-year-old man would hack his sleeping wife to death with an ax before fatally cutting himself with a knife in a grisly murder-suicide, according to authorities.

Bergen County Prosecutor John L. Molinelli said centenarian Michael Juskin killed his 88-year-old wife Rosalia late Sunday night with an ax on the first floor of the home. He then went to the bathroom and took his own life with a knife, according to the prosecutor.

Molinelli noted a history of domestic issues between the elderly Elmwood Park couple but said a motive has not yet been determined in the alleged murder-suicide.

Police discovered the bodies Monday morning after receiving a call from a family member, authorities said. Family members at the scene on Spruce Street declined to comment.

Neighbors told NJ Advance Media that Michael appeared more spry than his 100 years would suggest. He was often spotted walking around the neighborhood while his wife tended to the garden, neighbors said. The family spent winters in Florida with their children.

"It seems to be a nice family," one neighbor remarked.

The Sunday night incident marks what authorities say is the third murder-suicide in recent months to end with a husband taking the tip of a knife to his own flesh.

Bergen County prosecutors say 27-year-old Closter resident Michael Tabacchi in early February strangled and fatally stabbed his wife Denise Pars before turning the knife on himself. Their 15-month-old baby boy slept in the crib during the murder-suicide, prosecutors said.

Prosecutors in Somerset County concluded that John Sheridan, a prominent political figure and CEO of Cooper Health System, stabbed his wife Joyce multiple times before pouring gasoline in their bedroom and setting the room ablaze. He then fatally stabbed himself to death as the flames grew, prosecutors said. The sons of John and Joyce Sheridan dispute the findings.

Molinelli said the Elmwood Park investigation remains ongoing.

Appears Mr Juskin took Mrs Juskin life while she slept then took his own in bathroom. Axe used on mrs Juskin. Knife to Mr Juskin. — John Molinelli (@johnlmolinelli) April 6, 2015

History of domestic issues between Mr & Mrs Juskin but no knowledge at this time of motive. Occurred late yesterday. — John Molinelli (@johnlmolinelli) April 6, 2015

James Kleimann may be reached at jkleimann@njadvancemedia.com. Follow him on Twitter @jameskleimann. Find NJ.com on Facebook.